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Troubleshooting: Learn About DCC: Decoder Programming: Misc. Topics


Advanced Consisting (Using CV19)

Question: My consisted (MU'd) engines all blow their horns and ring bells at the same time regardless of what unit is leading. What gives?

If you use your command station to set up a consist and NOT the decoders themselves via CV19, it is expected that the headlights, horn, and bell will not behave 'realistically.' When using a command station to set up a consist, it often won't let you control a locomotive individually and instead always re-directs you to the whole consist. This can also result in undesirable behaviour, and will result in some amount of incompatibility between systems if you transport your consists) between multiple places.
When setting up advanced consisting using CV19 (sometimes included in the command-station-based consisting methods), the decoders will respond on TWO addresses.

  1. Address 1: The Base Address (as programmed to either short or long)
  2. Address 2: The Consist Address as programmed in CV19

On Address 1, all of the sound and light functions will respond all of the time on THAT decoder only. No decoder with a non-zero value in CV19 will respond to speed commands on their base address.
On Address 2, ALL of the engines on that consist address will respond to functions as programmed in CV21 and CV22. Speed commands must be sent on this address.

TCS' preferred recommendation and use case is to:

  • Save your non-consisted settings to a User Preset. (Sound Decoders Only!)
  • Set up the each of the DECODERS in your MU to a consist address by programming CV19.
  • Set up individual decoder's Consist Function Response using CV21 and CV22 if desired. (This step is optional.)
  • Save these new settings to a different User Preset. (Now you can instantly switch between single-unit and consisted operation by selecting a Preset without needing to touch CV's!)

Use the decoders' base addresses for functions like the light, horn, and bell (on the lead unit)
Use the consist address for speed control, brakes, muting, etc.

  • NOTE: Due to the reprogramming of CV21 and 22, the Audio Assist feature will break when controlled via a consisted address. It is for this reason that it is a requirement that our decoders always allow control of every function on the base address. The unit currently addressed will operate the Audio Assist features as expected regardless of the consist CV settings.
  • For Diesel decoders, you probably want to set the throttle mode to Traditional or Manual Notching to keep the engines' RPM in sync.

CV19, CV21, and CV22 are covered in-depth in the Comprehensive Programming Guide.

If you would prefer to use the command-station-based consisting method instead, use the following recommended practice for running two units (which you never plan to run from the trailing unit):

  • Save your non-consisted settings to a User Preset.
  • Turn on "Send Functions to Consist" in the command station's settings (if supported). If a user does not turn on "Send Function to Consist" in the settings, the ONLY thing they can control on any engine in the consist is the speed. No function commands are received (or sent) by/to the decoder when consisted in this way. If a user DOES turn on "Send Functions to Consist" in the settings, ALL functions will be sent to ALL the locomotives in the consist every time. If the decoder settings are set for CV21 and CV22 to receive all functions (as they are by default for TCS), they will indeed all work on every engine every time.
  • If you have any light functions which you explicitly NEVER want to come on under any circumstances, program the lighting effect CV for that function to 255 to disable it.
  • Set CV21 = 252 and CV22 = 60 on [Loco 2]. These settings should disable consist control of both headlights on the rear unit as well as the horn and bell. On [Loco 1], all commands respond all the time, even if [Loco 2] is selected. On [Loco 2], the headlight as well as the horn and bell will only operate when that loco is addressed directly, but when [Loco 1] is selected there will be no response. This setup assumes you will never be controlling your consist from the trailing unit.
  • Assuming the two units are oriented in such a way that the short hoods are opposite each other and the "lead" unit is selected, what may be expected is that in FORWARD, the forward light of the lead unit would be on, and all the lights on the rear unit would be off; similarly, in REVERSE, the Forward light on the "rear" unit would be on, and all the lights on the "lead" unit would be off. Essentially, the headlights on the "inside" are always off, and the lights on the "outside" are directional. This is how most people run their consists, but is open to modification based on personal preferences or the road of the prototype of course. To achieve this, you need to set CV50 on BOTH units on either end to 255 to disable their output. If you do so, the behaviour of the decoders will match the description above. You would think that it would be CV50 on the lead and CV49 on the training unit, but since the consist address will reverse the motor and lighting direction, it is in fact CV50 for both units. Note that these settings also work the same way if automatic Rule17 dimming is active.

If you plan to use three or more locomotives in a consist, and/or plan to operate the consist from either "end" depending on the direction, do the following:

  • Set CV22 on ALL members of consist to deny access to function 9 (and optionally 0, especially for DPU's, unless you have already disabled the light outputs you do not want to have come on). Currently, it is required that any directional headlights that you do NOT want to have turn on have their function outputs physically disabled in software using the corresponding CV's 49 and/or 50 with a value of 255. Alternatively, you can map the lights to different function buttons.
  • For consists with more than two members (including DPU's) Set CV21 to disallow control of Functions 1, 2, 3, and 4 on ALL members of the consist to prevent other engines from ringing bells or blowing horns. Only the addressed consist member should be allowed control if configured in this way.
  • NOTE: If functions of the decoder have been reassigned, or are preferred by the user to [not] be allowed control on a consist address, they may be disabled at said user's discretion in CV21 and CV22.

Tony's Train Xchange put together a helpful resource called the Complete Guide To Consisting that you may find quite enlightening.

Some throttles, such as TCS' UWT-100, or command stations offer configuration options on how to send specific functions to the consist address. Your throttle or command station manufacturer may offer instructions or documentation on how to change these settings.

Command Station Cannot Read CV's

Question: My command station says it cannot read the CV's from my TCS decoder. Why?

There are a few reasons why your command station may not be able to read CV values. Here are the top problems:

     Problem 1: Trying to program a sound decoder on a low-power program track without a booster.

Some systems on the market do not supply enough power for enough time on the programming track to allow for a programming operation to successfully take place. This is an issue especially for sound decoders or decoders with Keep Alive® which require more "juice" to program. This issue can be solved in most cases with a programming Booster. In our experience, the PTB-100 from Soundtraxx is a reliable option when used with our decoders and Keep Alive® devices.

     Problem 2: The motor is not connected to the decoder.

In order to communicate with the command station, a DCC decoder needs to generate a spike of current. This is done by pulsing the motor. If no motor is connected to the decoder, the decoder has no means by which it can "acknowledge" that a programming command has completed. Similarly, the decoder cannot communicate a CV value when requested that it be read. Therefore, it is important to make sure your motor connections are made and that they are free of short or open circuits. Shorts across the motor at this point can damage your decoder's motor outputs making them permanently unresponsive or run away! Open circuits will result in a similar lack of acknowledgement, and will also display an error on your system, but will not damage a decoder. For instructions on how to check your motor connections, visit the Multimeter Troubleshooting section.

     Problem 3: Locomotive is not on the programming track. (No, this is not a joke)

Without using a two-way communications method such as RailCom it is not possible to read CV values on your DCC mainline track. Writing CV's is possible, but not reading. This is because the command station and decoder do not have a method by which to communicate CV information on the main. Only command stations and decoders which support RailCom can communicate data on the main.

     Problem 4: The programming track is not physically connected to the programming track outputs from the command station.

On some DCC systems, your main track and programming track might be combined; however, most systems use a second set of connections for dedicated programming tracks. If you have not connected your programming track to these outputs, or if there is a loose/broken connection, your programming track will not function.

     Problem 5: Decoder lock is active.

Decoder Lock is a NMRA standard which allows for a decoder programming to be "locked" and therefore disallowed. When a decoder is locked, all CV values other than CV15 and CV16 will report "Cannot Read CV" or similar. More information on Decoder Lock can be found on the NMRA List of Standard CV's or in TCS' Comprehensive Programming Guide.

Question: I use JMRI and I cannot read CV's reliably if at all. Does this still apply?

Yes! JMRI Decoder Pro relies on your command station to do all the heavy lifting of reading and writing CV's. All of the issues and advice above still applies even if you use JMRI to program your decoders.

However, it is also important to keep in mind that JMRI is constantly evolving, and is a program developed by volunteers. As decoder manufacturers such as TCS continue to release new decoder types, versions, and features, those options will be added to the JMRI "decoder definitions" over time. As such, it is imperative that you keep your Decoder Pro and JMRI software up to date with the current release. The latest bug fixes and decoder definitions can make the difference between quick success and endless frustration when programming a decoder.

Question: Why can't Decoder Pro identify my decoder?

See the above point about decoder definitions and CV read-back troubleshooting. If your version of Decoder Pro does not have the specific decoder or decoder version available in its list of definitions, the program will not be able to successfully identify your installed decoder. Make sure that your JMRI version is up to date with the latest available. You can download the latest version from JMRI's Website.

Mainline Programming

Programming an address "on the main" is complicated for a few reasons. The first complication is that CV number 1 may never be programmed on a mainline in OPS mode - This is a DCC standard set by the NMRA. Therefore, if you plan to program a short address, you must use a programming track. If you want to program a long address into a decoder using your mainline, see our help section on Four digit Addressing. Mainline programming is 100% reliant on the address of the locomotive to perform programming. Here are the problems with that:

  • Having multiple decoder on the same address
  • Having multiple decoders in the same engine
  • Not knowing what the address is/Accidentally scrambled the address
  • Selecting the wrong address and instead programming a different decoder by mistake

When setting addresses, TCS recommends only using a programming track and never re-configuring the address on the main.

The only benefit of mainline programming is the speed at which programming operations can be performed. It is not necessary to wait for confirmation or read-back on each operation. Unfortunately, the trade-off is that without the technology such as RailCom it is not possible to perform mainline program read operations. Mainline programming is only recommended for on-the-fly changes that need to be performed in real time or if you are experienced with CV programming.


DC Operation on TCS' DCC Decoders

Question: Can my TCS DCC decoder run on DC power?

Yes! All TCS decoders are capable of operating on DC track power. This configuration is enabled by default on all non-sound TCS decoders. CV29 can be modified to enable or disable DC operation on any TCS decoder.

Question: Why is my WOWSound locomotive not operating sound functions on DC?

With the exception of OEM decoders/projects such as the Bachmann ACS-64 and Streamlined K4, version 4 and older WOWSound decoders do not feature DC sound operation.

Question: Can I program lighting effects on DC?

While it is not possible to perform CV programming or Audio Assist programming on DC, any configurations set on DCC will carry over to DC. For example, if your engine has been programmed to operate a Mars light, firebox flicker, or directional lighting, those settings will carry over into DC operation and behave as if on DCC.

Question: My DC motor/lighting is reversed but it works fine on DCC. Why?

On DCC, the track power is AC with encoded data and as such is not polarized. Due to this, the engine and decoder are only aware of what direction they are/should be going based on the information sent by the command station. Therefore, "forward" is merely a perspective. Conversely, on DC the track power is polarized. TCS decoders detect the (+) track power rail and base the direction of the motor and lighting depending on which rail is positive. If the track power leads (Red and Black) or motor leads (Orange and Grey) are connected backwards of their intended polarity, the decoder's interpretation/assumption of polarity will be backwards of reality and should be fixed. Make 100% sure your wires are connected properly if you plan to run on DC frequently or exclusively.

Decoder Resets

Question: My decoder is acting erratically/My decoder won't respond - How do I reset my TCS decoder to factory settings?

Factory resets on ALL TCS decoders are performed by programming CV8 with a value of 2.

NOTE: CV8 is what the NMRA defines to be a "Read Only" CV. What this means is that no value can be used to overwrite the value in this CV; however, TCS has defined several "macros," or sequences of operations which will be performed in the even specific vales are attempted to be programmed. For example, by programming a value of 2, a factory reset will be performed.

Note: Any TCS decoder manufactured on or after July 1st of 2019 support the use of values of 2 or 8 in CV8 to perform a factory reset.

On TCS WOWSound decoders, a "nuclear reset" can be performed by programming the following CV's:
CV201 = 5
CV202 = 0
CV203 = 0
CV204 = 8

A nuclear reset will change 100% of the configurations of the decoder. Due to time constraints in certain circumstances, a standard factory reset has been designed to ignore certain CV's and settings. The reset above will load User Preset 1, thereby overwriting everything. If no configurations were previously saved to User Preset 1, the decoder will be loaded will all default settings.

Before performing a factory reset, you may want to make you you have checked our section on Addressing first! In some situations, a full reset may not be necessary. If for example the issue(s) began after changing the decoder address, it is likely no other problems exist. To reset your decoder address only, ensure CV19 = 0, then Program CV1 to 3 on a Programming Track. Programming tracks ignore addresses and are the only way to resolve address issues. For other tiers of resets, such as resetting throttle buttons to their default sounds, Audio Assist can be used to reset certain parts of your configuration.

Decoder Documentation and the Documents Tab

Question: Where can I find programming guides and documents for my TCS product?

By searching your product on our website, you can visit the "Documents" tab to see all of the related literature, documentation, and programming guides for your decoder.

When visiting any product on our website, just click the "Documents" tab on the product page. On this page, you will see a list of links to all of the relevant documentations for that particular item. For example, a sound decoder will have:

  1. Basic decoder literature
  2. The Comprehensive Programming Guide
  3. The Complete Sound Guide for that sound type (Steam/Diesel)
  4. The full list of sounds for all individual Versions
  5. The Audio Assist tree diagram for that sound type (Steam/Diesel - Current production version only)
  6. The 4-CV Guided programming tool for that sound type (Steam/Diesel)

We also offer specific pages for decoder documentation. Follow the links below to visit the listings for:

Decoder Documentation
Decoder Programming Tools & Resources
TCS' Documentation Wiki

Decoder Selection - WOW101 vs. WOW121

Question: What is the difference between a WOW101 and a WOW121?

WOW101 and WOW121 decoders are identical in practical application, meaning they are both capable of providing the same power output, same sounds, and same motor and lighting characteristics. The fundamental difference between them is that the WOW121 relies on a 21-pin motherboard to interface with a locomotive. If you are someone who is planning to 'update' a DC-only model to DCC, there are a few factors to consider:

  • Does this locomotive have a mounting solution for a motherboard, such as a clip or flat surface above the motor?
    • WOW101 decoders are intended as direct plug or hard-wire installations. If the locomotive features a mounting solution for a motherboard, that option is preferable.
  • If I use a motherboard, will there be enough clearance to put the shell back on?
    • TCS decoders fortunately feature an industry-leading low-profile design, and as such can fit into lower shells and tighter spaces much more easily. If width is a concern and a motherboard will not fit, WOW101 decoders are slightly narrower and may be preferable.
  • Do I need to re-motor?
    • If you need to replace your existing drivetrain with a newer or upgraded drivetrain, that system may have a mounting solution. See Point 1.
  • Would it be easier to wire my components directly?
    • Some times it's easier to just run wires directly to the pickups for track, motor, lights, etc. into a single harness rather than individual wires. If it is preferable to wire direct, the WOW101 is likely the better option.
  • Am I going to replace any bulbs with LED's?
    • TCS motherboards have on-board resistors for use with LED's. WOW101 decoders do NOT have integrated resistors. If using anything other than 12V bulbs, external circuitry/resistors MUST be added.

Your answers to these questions will determine if a hard-wire job or a kit installation are right for you and for your locomotive.

Question: I have (x) locomotive. What decoder do I need?

First answer these questions:

  • What scale?
  • Do you want sound?
  • Will this engine be run on DC or DCC?
  • Have you searched our Installation Resources for your model?
    • If you answered "Yes" to sound, search only the WOWSound Installations.
    • If you answered "No" to sound, select your scale.

Use the search box at the top of the page to narrow the list down by manufacturer or locomotive type. We recommend browsing by manufacturer to see all of your options.

I wasn't able to find my specific model. Now what?

If you cannot find your specific model in our list of installations, you can submit pictures of your model with the shell removed to our team via Facebook or via Email

Decoder Addressing

When programming a decoder address, there are two address "ranges" you can program: Two-digit "Short" addresses, and Four-digit "Long" addresses. The word "digit" refers to the number of 4-bit "nibbles" used to represent the address in binary. The word "digit" does not mean there needs to be specific numbers in your address! The address type, short or long, is configurable using CV29. By default, a decoder ships in the two-digit "short" addressing format with a value of 3.

Short Addressing:
The two-digit "Short" address is stored in CV1 and has a valid range of values from 1 to 127. A value higher than 127 is invalid for short addressing. If you would like to program your locomotive with an address (such as a road number) which is greater than 127, you must use a 4-digit "Long" address. Per the NMRA spec, CV1 cannot be modified on the main via operations (OPS) mode programming; therefore, you must use a dedicated DCC programming track to make that change.

Long Addressing:
A 4-digit "Long" address may be any address between "0000" and "9999". That does mean that you may have overlapping values between short and long addresses. For example, long addresses with values less than 128 are typically expressed with an asterisk (*) or placeholder zeroes. The default long address is 0000. Since a long address uses four "digits" that means it also uses two CV's. The CV's used to set a long address are CV17 and CV18. To enter a long address manually, you first need to convert the road number or other desired address number to "binary-coded decimal" using a calculator tool. You may use the values calculated for CV17 and 18, and enter them into CV17 and 18 to set the address.

After those values have been entered, you need to change the addressing type for that decoder to LONG addressing. If you have not changed the default configurations, program CV29 with a value of 34. If you have, or aren't sure, first READ CV29, and then ADD 32. Program the SUM into CV29. You can also use our CV29 calculator to determine the necessary value based on your desired configurations:

CV29 Calculator

Some command stations have a method of automatically entering a 4-digit "Long" address which will automatically calculate and program these values, including CV29. You can refer to your command station user manual or manufacturer for more information. In most cases, you can program a long address with a value of less than 128 IF you add the placeholder 0's when programming. Ergo, a value of 28 would be programmed as 0-0-2-8. It is a common issue to have your command station automatically change the address type based on the number address you enter.

Note: If you do mainline address programming, ANY value entered will become a long address*

Question: I programmed my address but lost control of my decoder. Now it won't respond to my commands!

In this situation, it is likely that a button was not pressed correctly or the programming was not completed successfully; additionally, if you programmed your address on the MAIN using OPS-mode programming, the address programmed into the decoder will ALWAYS be a long address (even if the address number was less than 128). As mentioned previously, short addresses MUST be programmed on a DCC Programming Track, and cannot be modified on the main per the NMRA standard. If you have programmed a long address that is within the short address space (0 to 127), you need to include the placeholder 0 when selecting your address. For example, long address 3 would be selected by entering "03" rather than just "3" when entering the address into your throttle. Similarly, long address 100 would be selected by entering "0100". DO NOT enter the placeholder "0" if you wish to select a decoder with a Short Address programmed.

If you have lost or scrambled your decoder address resulting in a loss of control of your decoder, TCS decoders allow for a simple resolution! By placing your locomotive on a DCC programming track, you can reprogram CV1 to a valid value in order to revert the addressing. For example, if you write a value of 3 to CV1, the decoder will revert to short addressing on the default address of 3. All TCS decoders behave in this way.

*Note for Digitrax users: Digitrax command stations do not support Long Addresses within the range of 0000 to 0128. If you have a locomotive with an address within this range, it will not operate and cannot be selected on the system. Additionally, if you attempt to program an address between 1 and 128 on the main, the programming operation will not take place or could result in a random address being programmed instead.

Understanding Light Functions

TCS decoders follow the NMRA standards and specifications for lighting functions, including the color code. For a full list of NMRA wire color codes (and the function outputs they correspond to, click Here. While it may not make sense on some products without wires, it can be more complicated to define functions as "functions" due to the confusion between sound functions, light functions, and physical buttons on your handset.

To clarify, I like to delineate numerical functions like this:

  • A "Button" with a number (0 -> 28) corresponds to the numbered "buttons" on the throttle or other controlling devices. On a physical throttle these would be the numbered buttons on the handheld. Similarly, in JMRI Decoder Pro this is the throttle you can pull up and use from your computer. If you use a cellphone or tablet, these are the buttons you can press on your screen.
  • A "Function" is typically defined as an electrical output from a decoder. Sometimes, "functions" can be referred to as "outputs" for better clarity and to limit the confusion with sound functions. Numerals are assigned to each output to distinguish it from the rest. On an 8 function decoder, you have two "0" functions for forward and reverse per the NMRA standard. (0F and 0R count as TWO functions. 2 + 6 = 8)
  • A "Function" and a "Button" are NOT required to be linked together. Functions may be assigned to other buttons using the remapping CV's. As an example, for Function 1 and Function 2 these CV's are 35 and 36 respectively. A value of 4 in both of these CV's will remap both of the function outputs to respond on Button 1 on your controller. HOWEVER! A "Function" will ALWAYS retain the same lighting effect CV as its output number. For example, CV51 corresponds to Function 1 and CV52 corresponds to Function 2. Regardless of what button these function outputs are mapped to, their effect CV's will continue to reflect their "Function" number.

TL;DR: "Function" = electrical output from decoder | "Button" = physical numbered button on controller

All light functions can be remapped or reprogrammed for your desired operation. For more in-depth details on function remapping and output assignment, I would highly recommend browsing through our Comprehensive Programming Guide. This guide covers all the essential information pertaining to basic decoder configuration, as well as how to assign function outputs and effects. See our help section on Function Remapping for more info.

Function Remapping

Function mapping of lighting outputs can be done via the programming of Configuration Variables or via Audio Assist on WOWSound decoders. The chart found in the Comprehensive Programming Guide shows the CV's and values that correspond to the function outputs and function buttons. In the DCC standard for packet transmission (that is, the communication over the rails) function buttons for lighting are separated out into two packets, with functions 0-6 being in the first packet, and Functions 7-12 being in the second packet. As such, if a function is going to be assigned to respond to a command in one of these packets, it needs to be configured in that CV. As you see on the chart, Functions 1 - 6 have TWO CV's. The CV on the LEFT of the chart can assign a button from 0 - 6 to that function. A value of ZERO in any of these CV's will disable the function from responding to any button from 0 - 6. Along the RIGHT of the chart are the secondary CV's which correspond to buttons 7-12. By default, these CV's are 0. By programming a value to these CV's, a button or buttons can be assigned to activate the function from 7-12. Note that it is possible to have multiple buttons control the same function using this method if desired. It is suggested that only one CV for each function be programmed with a non-0 value to prevent de-synchronization or confusion.

Along the TOP of the chart are two sections of values from 1 to 128. The numbers from 0 to 12 listed above the values state what value would correspond to that button number. By programming the value listed below a button number, that button will be assigned the function whose CV was just programmed.

It is important to know the difference between a FUNCTION and a BUTTON.

  • A FUNCTION corresponds to a numbered function pad or a colored wire from the decoder. For details on which color of wire corresponds to a numbered function output, refer to the NMRA Wires and Connector Standards
  • A BUTTON is located on your throttle or control device and does not necessarily directly correspond to any output from the decoder, as this can be configured.

[Example: You are attempting to move a function to the higher function group. F2 -> Button 8. To do this, once again look at the chart. Function 2 has two CV's - CV36 and CV38. Button 8 is part of the higher functions, which would make use of CV38. Therefore, by selecting the value that corresponds to Button 8 (a value of 8), and programming that value into CV 38, Function 2 will now respond to Button 8. To finish the transfer, we need to clear the button from responding to Button 2. To do this, program CV 36 with 0. Now you are finished!]

Using the WOWSound "Rotate" Feature

The rotate feature on a WOWSound decoder allows you to quickly cycle through all of the whistles, horns, or bells on the decoder. The number of whistles, horns, and bells on your decoder will vary based on the Version and type. (Steam/Diesel/OEM/etc.)

To use the Rotate feature, play a horn/whistle or bell sound, then press the Rotate button (default is 9) to begin cycling through the available sounds. When rotating horns/whistles, Audio Assist will announce the new selected horn/whistle set; Rotating bells will play a sample sound of the new bell. Once the rotate button is pressed, the new set is locked in automatically. The Rotate feature will change the entire set of horn/whistle sounds at the same time. (That includes the long, short, crossing quills, and directional quills.) The Rotate feature will rotate through the available sounds in alphabetical order. You may use the direction key on your throttle to change the order of the rotation. For example, setting the throttle to reverse will cause the rotate feature to begin cycling through the sounds in reverse alphabetical order. You may use this to "go back" if you found something you liked and do not want to go all the way around again, or if you want to go to one of the last options on the list more quickly.

To watch our video demonstration of the Rotate feature, click here: WOWSound "Rotate" Feature Video Tutorial

Heat and Decoders: How Hot is Too Hot?

Question: How hot should my sound decoder get?

WOWSound and other TCS decoders should never get hotter than can be touched comfortably. You should be able to grab a hold of the decoder and not burn yourself; however, our decoders can get up to about 100 degrees based on the conditions presented to them without much of an issue - that would be a normal operating condition.

Things to look for would be the origin of the source of the heat. If your decoder has shrink wrap, look for places where it may be stretched - indicating heat is prevalent in that area. Also, if the amplifier is being "taxed" or overdrawn, it will get very hot. Conditions that would cause this would be:

  • Using a speaker which is rated at less than 8 Ohms and less than 2 Watts
  • Pumping 100% volume into a speaker which is not rated for 2 Watts or greater
  • Having a speaker with a loose cone or similar mechanical failure

These are the leading causes of excessive heat in regards to the audio amplifier. As a test, you can disconnect the speaker, or mute the decoder for an extended period of time to see if it cools off.

WOWSound audio amplifiers can supply upwards of 2.2 Watts of power at 100% volume into an 8 ohm speaker. If your speaker is not rated for 2 or more Watts, but is being supplied with a 100% volume output, the sound will distort and possibly pop and click.

If you are hearing distortion in the sound quality and/or have a hot decoder, it is recommended to reduce your master volume by at least 10%. If you are still hearing distortion or clicking when playing loud sounds like a longhorn/longwhistle, reduce by an additional 5% until it goes away. Each press of button 1 in the master volume menu of Audio Assist reduces the master volume by 5%. Don't forget to save your changes with button 8!

The resistance across the speaker should read between 7.2 and 8.8 Ohms. Readings outside of this range would indicate a failed speaker.

Note that there are also two high-probability failure conditions for speakers:

  1. Overdriving - If too much current is being passed through a voice coil that it is not rated to handle, it will fail immediately, or over time as the insulation on the wire or physical cone material breaks down. Our amplifiers put out over 2 Watts at full volume when playing loud sounds. Take note of the Wattage rating of your speaker and reduce your master volume as needed.
  2. Heat - When soldering wires to a speaker, it is best to overheat your iron in order to reduce your contact time. If your iron is too cold, it will increase your contact time, and result in more heat transferred into the voice coil and connecting wires. This can break down the insulation, or physically detach or break the wire at/near the pads on the speaker itself. We at TCS run our irons at 720 degrees F or higher to minimize contact time.

Problem: I tried these steps above and the decoder did not cool off.

If the heat source is not related to the audio amplifier, meaning it is still hot while the sound is muted for a long time or the suggestions above have made no difference, you may consider the following:

If the decoder is only hot after running for LONG periods of time, this is a reasonable condition and should not damage the decoder. Failures related to motor control tend to happen quickly, so if you can observe reliable long-term operation, there should be no reason for concern. Give your engine a break every once in a while or at slower speeds if you are concerned.

If you are not observing excessive heat during stationary conditions, it is likely that the heat is being created by the motor drives which is normal. If the heat is excessive, you may consider testing your motor current draw. Next check the current rating of your decoder to make sure you are not exceeding its capabilities! Current ratings of decoders can be found on their product page under the tab labeled "Specs". Note that these current ratings are for the entire power supply - motor, lights, and sound if applicable.

Keep Alive® Compatibility

NOTE: ALL TCS decoders are compatible with Keep Alive®! Yes that includes N and Z scale and Fleet Lighter decoders! All TCS decoders are also defaulted to support Keep Alive® without any programming. Just plug and play! This is not true for all manufacturers and decoders! If you are unsure if your decoder supports Keep Alive® you should contact your decoder manufacturer.

Keep Alive® supporting code for TCS decoders was implemented fully by November 2012. If the date code in your decoder is before this date, Keep Alive® may never enable. Other decoder manufacturers have since followed with their own support for the device. You may need to consult your decoder manufacturer regarding their own support for Keep Alive® on specific devices. CV's 250, 251, and 252 read as the month, day, and year of manufacturing.

If you would like to attach a Keep Alive® unit to a non-TCS decoder, you need to connect the wires across the output of the bridge rectifier on the decoder. You will need to consult your decoder manufacturer for a schematic or wiring diagram if you are not able to locate these two points on your decoder:

  • +12Volt DC Common (Blue wire on KA devices and most DCC decoders)
  • Decoder Ground (Black & White wire on KA devices)

If you are able to find these two points on the decoder, solder the two Keep Alive® wires and you are finished. If you are not able to locate one or both of these connection points, your decoder manufacturer may be able to provide guidance or a schematic.

Keep Alive® is a DC voltage device. Do not connect the wires from your Keep Alive® device to track power! Attaching the unit to track power will do nothing if not destroy the unit.

All Keep Alive® devices operate in the same way and are equally compatible with any decoder. KA1 and KA2 devices have equal capacities to each other, and are approximately 1/3 the capacity of the KA3 and KA4 devices while at the same time being roughly half the size of their counterparts. Physical dimensions are the only considerable differences between Keep Alive® devices. These dimensions must be taken into account prior to installation, as choosing the wrong device may interfere with the installation.

For more information on Keep Alive®, click Here.

For more information on our new KA1 and KA2 devices, click Here.

Light Mode vs. Sound Mode

Question: I hooked up my lights on my WOWSound decoder but I cannot turn them on. What gives?

NOTE: If you are looking for assistance or advice on wiring your locomotive, see the sections below for wiring LED's or incandescent lamps.

WOWSound decoders have two operational modes: Light Mode and Sound Mode. When first powering up a WOWSound decoder, it will default to Sound Mode. In order to access your light functions beyond F0, you must enter Light Mode. (Unless otherwise user-configured)
To toggle operational modes, you must press Button 8 on your controller twice in rapid succession. You will hear an announcement from Audio Assist® announcing the active mode. In order to change back, just press button 8 twice again. If you switch too fast, however, the decoder may register 4 presses and enter the Audio Assist® program.

In sound mode, you can use buttons 0-28 to control sound functions. In Light Mode, you can use buttons 0-12 to control lighting functions. Both modes can be remapped using Audio Assist or CV programming, but you should refer to your decoder literature for the default mappings. By default, Light Mode buttons will correspond directly to their numbered function output unless otherwise programmed. By default, ONLY function 0 will respond to commands in both Sound Mode and Light Mode. In order to use any other function button in both modes, that button must be "dual-enabled" using CV programming. For assistance on CV programming function buttons into dual-mode, visit the Guided Programmer for your decoder type:

Programming Tools

Question: Function 2 doesn't work?

Most likely, lighting Function 2 of your decoder is working. Some command stations and throttes such as Digitrax set Button 2 as a momentary function (not latching). You can confirm this by holding the button down to see if your light remains on.

Okay so how do I fix that?

The simple solution is to remap your light to another button. Otherwise, the instruction manual for your throttle or command station should tell you how to change the momentary function to a latching one.

To learn more and see a demonstration of Light Mode and Sound Mode, check out our video on WOWSound Operational Modes:


Lights - The Rules of Wiring Incandescent Bulbs

The precise wiring of your locomotive's light functions is ultimately at the discretion of the end user. However, a few rules do apply. When using incandescent bulbs, observe the voltage rating - 12V bulbs must be connected to the 12V supply. Incandescent bulbs rated for 1.5V may be connected to 12V, but only through a resistor with appropriate ratings for the rated current of the bulb; alternatively, a TCS VR1.5, or an on-board 1.5V source may be used to provide a regulated 1.5V supply for all of your lights. Some TCS motherboards have dedicated 1.5V power supplies on-board for these bulbs, but not all motherboards. Additionally, some motherboards have dedicated contacts for "Bulbs." These dedicated bulb outputs bypass the on-board resistors for use with LED's which would otherwise prevent the bulb(s) from lighting.

If you are installing an Athearn locomotive which has not had the factory bulbs replaced, you should use the 1.5V power supply as the positive voltage source for your lights. Athearn throughout most of their history has used 1.5V incandescent bulbs, with only a very recent transition to LED's. As such, the 1.5V power supply indicated on the motherboard, plus any correspondingly labeled "Bulb" pads are to be used for these models. The GEN-MB1 and RTR-MB1 motherboards designed for use in the Athearn Genesis and Ready-to-Roll/Blue-Box lines include onboard 1.5V power supplies for this reason.

Incandescent bulbs, unlike LED's, are not polarized, meaning they can be connected with either wire to either pad. It is common for a locomotive manufacturer to bundle together one wire from each light and tie it to the source, then run a single wire from each light to the functions. The same applies to a replacement motherboard. When wiring a TCS motherboard, follow the same practice, connecting one wire from each incandescent light to the appropriate Voltage source, and the second wire from each light must then be run to its own respective function output as described in our Understanding Light Functions section.

The NMRA standards and specifications designate the use of White and Yellow wires for headlights. To White is assigned "Function 0 Forward" for use with a forward headlight, and to Yellow "Function 0 Reverse" is assigned for use with a reverse headlight. If your decoder does not use wires (motherboards for example), the literature for your product will include a wiring diagram designating what connection(s) correspond(s) to a function. For a full list of NMRA wire color codes, click Here.

All light functions can be remapped or reprogrammed for your desired operation. For more in-depth details on function remapping and output assignment, I would highly recommend browsing through our Comprehensive Programming Guide. This guide covers all the essential information pertaining to basic decoder configuration, as well as how to assign function outputs and effects. See our help section on Function Remapping for more.

TCS connectors and harnesses are available with colored wires to connect lighting and other functions. You can view our page listing all of our wiring and connector standards by clicking HERE.

Lights - The Rules of Wiring LEDs

The precise wiring of your locomotive's light functions is ultimately at the discretion of the end user. However, a few rules do apply.
When using Light Emitting Diodes (LED's), you must always include a resistor in series to limit current UNLESS your TCS product has on-board LED support. Refer to your decoder literature, wiring diagram, or the silk screen on the board itself for LED connection points (if applicable).

If using Light Emitting Diodes, polarity must be observed, as a reversed connection will not work. Diodes have two connections known as the Anode, which is a (+) connection, and Cathode, a (-) connection. When working with decoders, the Anode(+) connection is to be connected to a common voltage source, and the Cathode(-) connected to an individual function output. These connections will be noted in your decoder literature or on the silk screen of the product itself. The NMRA determined that DCC decoders are to be designed as "Common Anode" devices, meaning there is to be ONE, COMMON, POSITIVE voltage source, and individual returns to ground(-).

BLUE is the color designated by the NMRA to be used for the common Positive Voltage Source. On decoders, this can be designated as a Blue wire, "BL" or "+", or similar. As many lighting functions as needed are to be wired to this one point. Some decoders have multiple connection points for ease of installation. TCS decoders, unless otherwise specified, use an un-regulated +12V DC power supply to power the lighting effects. This power supply is fed directly from the rectified track voltage; therefore, the voltage of this supply will vary based on your track voltage and can be assumed as ~1.5V less than your AC track voltage.

Each function on a decoder is given an associated color and function number to serve as a return to ground. When using LED's, these connections must be made to the cathode (-). If your decoder requires external resistors for use with LED's (not LED-ready), you should always connect the resistor on the cathode (-) side of the LED to prevent current surges into other connected functions as a result of a lighting effect cycle or a function turning on or off.

LED's are current-driven devices, not voltage-driven devices. This means that the voltage across your LED will always remain constant as determined by the LED's voltage rating itself. The brightness of an LED will be determined by the current flowing through the circuit. The current passing through a lighting function is determined by the resistor value used. Following Ohm's Law, we know that the current is directly proportional to the voltage, and inversely proportional to the resistance. If you know the voltage rating of your LED, subtract that from the total voltage in the circuit (we can assume 12V) and divide that value by the resistance to yield your current. All of TCS' LED-ready products (that includes decoders and motherboards) are fitted with 1000 Ohm resistors. This value of resistance yields fine results with just about any LED. If you are using aftermarket LED's, it is recommended that said LED be rated between 1.5V and 6V, with the typical rating being 3V.

The NMRA standards and specifications designate the use of White and Yellow wires for headlights. To White is assigned "Function 0 Forward" for use with a forward headlight, and to Yellow "Function 0 Reverse" is assigned for use with a reverse headlight. If your decoder does not use wires (motherboards for example), the literature for your product will include a wiring diagram designating what connection(s) correspond(s) to a function. For a full list of NMRA wire color codes, click Here.

All light functions can be remapped or reprogrammed for your desired operation. For more in-depth details on function remapping and output assignment, I would highly recommend browsing through our Comprehensive Programming Guide. This guide covers all the essential information pertaining to basic decoder configuration, as well as how to assign function outputs and effects. See our help section on function remapping for more.

TCS connectors and harnesses are available with colored wires to connect lighting and other functions. You can view our page listing all of our wiring and connector standards by clicking HERE.

Setting Up Ditch Lights on TCS Decoders (Non-sound Version 88 and newer; WOWSound V4 and Older)

Ditch lights are very common on modern Diesel locomotives. Many models available in the market today come factory equipped with at least one pair of operational ditch lights. By default, TCS decoders are configured to output a constantly bright light on all lighting functions. If the road you are modeling has constantly bright ditch lights that simply turn on and off, you can ignore this section. If you are modeling a road which has alternating/blinking/flashing ditch lights, this section below will give you the CV values to program those lights.

Question: How do I turn on my ditch lights on my TCS WOWSound decoder?

Hold your horses! Before we get to turning on the lights, lets make sure they are connected and programmed! To make sure everything is in good working order, let's go through a couple of setup steps. First, TCS recommends connecting your ditch lights to the following lighting outputs - Function 1 & Function 2 for forward, and Function 3 & Function 4 for reverse (if applicable). For instructions on hooking up your lighting functions to a TCS decoder or motherboard, visit the sections for either LED's or Incandescent Lamps.

Once you have your ditch lights physically connected, we can get down to programming! The easiest way to set up your ditch lights is by using TCS' quick preset for ditch lights. Most users want their ditch lights to flash if the Horn button is pressed. By using this preset, a WOWSound decoder will operate in this way. The quick preset will automatically perform the following sequence. You do NOT need to manually enter this sequence unless something goes wrong.

STANDARD Omni-Directional Lights Tied to F1

To set up GREEN and VIOLET: (Turn on/off with Button 1 [in light mode for sound decoders])
    • CV35 = 4 - Function 1 on/off with Button 1
    • CV36 = 4 - Function 2 on/off with Button 1
    • CV51 = 42 - Ditch Light Side 1 (Bi-Directional)
    • CV52 = 43 - Ditch Light Side 2 (Bi-Directional)
    • CV124 = 8 - BLINK ON BUTTON 2 ONLY
FOR SOUND DECODERS, To set up Button (2) to work in both light & sound mode, program in order:
    • CV201 = 4
    • CV202 = 14
    • CV203 = 2
    • CV204 = 11 = DUAL ENABLE BUTTON 2
All of the above configurations will be set automatically if you program CV8 with a value of 10. The ditch lights will turn on and off on Button 1 and will not turn off in the reverse direction.

For models which have four ditch lights - one pair in the front and one pair in the rear, the above sequence needs to be modified. For example, the lights may need to be set to be directional. To set this up, use the following programing steps:

To set up GREEN and VIOLET: (Turn on/off with Button 1 [in light mode for sound decoders])
    • CV35 = 4 - Function 1 on/off with Button 1
    • CV36 = 4 - Function 2 on/off with Button 1
    • CV51 = 10 - FWD-ONLY DITCH LIGHT
    • CV52 = 11 - same as above
    • CV124 = 8 - BLINK ON BUTTON 2
To set up PINK and BROWN: (Turn on/off with Button 1)
    • CV39 = 4 - Function 3 on/off with Button 1
    • CV40 = 4 - Function 4 on/off with Button 1
    • CV53 = 26 - REV-ONLY DITCH LIGHT
    • CV54 = 27 - same as above
FOR SOUND DECODERS, To set up Button 2 to work in both light & sound mode, program the following sequence in order (If you programmed CV8 to 10 already, you do not need to program the following!):
    • CV201 = 4
    • CV202 = 14
    • CV203 = 2
    • CV204 = 11

If you would like to have your ditch lights operate on Function 0 (headlight) rather than Function 1 in light mode, set the following during or after the previous sequence:
    • CV35 = 1
    • CV36 = 1
    • CV39 = 1
    • CV40 = 1

TCS WOWSound decoders offer 3 horn/whistle buttons by default on Buttons 2, 3, and 4. If you would like to set up the ditch lights to operate when ANY of those buttons are pressed, you need to modify the sequence(s) above with the values below during or after the previous sequences:

    • CV124 = 56 - Blink Ditch lights on Button 2 OR 3 OR 4.
    • CV201 = 4
    • CV202 = 14
    • CV203 = 2
    • CV204 = 59 - Dual-enable Buttons 2, 3, and 4

Now that we have completed our programming, we can turn the lights on! If you have configured your ditch lights to operate with the headlight, just turn your headlight on and you are done! If you have a TCS WOWSound decoder and have programmed your ditch lights to a different function button, you need to go into Light Mode.


Marker Lights

A common request we receive is marker lights that are active in the opposite direction of travel. The directionality of lighting effects is based on the value entered in for that lighting effect generator. CV's 49-56 can be programmed with values to determine the lighting effect as well as the direction of that lighting effect. For example, a constant bright light in the forward direction equates to a value of 0; in the reverse direction, this value is 16, and for both directions (the default value for CV's 51-56) 32.

For the above case, light functions tied to the lights opposite the direction of travel need to be programmed with the value which corresponds to the direction of travel. For example, the lights on the rear of the engine would be programmed to be ON in forward, and the lights on the front of the engine would be programmed to be ON in reverse.

Please consult page 7 of the Comprehensive Programming Guide for the full chart of effects and the corresponding directional values.

Manual Calibration (WOWDiesel)

It is possible to "dial in" the BEMF calibration via CV programming. If the automatic calibration didn't quite get it right, you can manually modify the BEMF settings. To do this, perform the following operations:

It is necessary to first know the existing calibration values prior to adjusting them so that you are not programming randomly or blindly.

CV201 = 104
CV202 = 17
CV203 = 0
CV204 = 0
READ CV204: This is your current LOW BEMF setting "idle setting" in which you will be notch 1. Decreasing this value will mean that notches 2-8 will happen sooner with lower loads. Increasing this value will require more "load" to increase the notch.

CV201 = 104
CV202 = 18
CV203 = 0
CV204 = 0
READ CV204: This is your current HIGH BEMF setting "notch 8 setting." Decreasing this value will decrease the dynamic range, resulting in faster notch transitions.

CV201 = 4
CV203 = [17 OR 18] (High/Low BEMF setpoint)
CV203 = 0
CV204 = [Your Desired Value]

It is advised to work in steps of +/- 5. If you find that you have gone one step too far, go backward by a value of 2.

Additional information on how to manually calibrate can also be found in our WOWDiesel Programming Guide.

Decoder Lock

The Decoder Lock feature is used to change CVs in only one of several decoders with the same short address (CV1) or long address (CV 17 and CV 18). Typically this becomes a concern only when multiple decoders are installed in the same locomotive. An alternative reason to use Decoder Lock is if you fear that another person may attempt to program your decoder on accident (or on purpose), and you want to prevent that from being possible.

The WOWSound Version 5 decoder includes an exclusive new feature which will play an audible warning if you attempt to program a CV while Decoder Lock is active.

To Lock a Decoder:

  1. Program a number between 1 and 6 into CV 16 in each decoder (see the chart below for the standard values) before the decoders are installed in the locomotive.
  2. Set CV 15 to a value which does not match CV 16, or use a value of 7 to ensure the decoder is locked.
  3. The decoders will individually compare CV 15 to CV 16 and, if the values are NOT equal, the CV values of that decoder may NOT be manipulated.

To Unlock a Decoder:

  1. To change a value in another CV of one of the installed decoders, first write the corresponding number into CV15 which matches the value in CV16 for the decoder you wish to program.
  2. Set CV 15 to a value which matches the CV 16 value for the decoder you want to program. You may also use a value of 0 in CV 15 if you want to program all of the decoder simultaneously.
  3. The decoders will individually compare CV 15 to CV 16 and, if the values are equal, the CV values of that decoder may be manipulated.

Important things to know about decoder lock:

  • By default, a DCC decoder will be unlocked, but may or may not have a value set in CV16. The Value in CV15 must be equal to CV16 in order to read or write CV values.
  • If Decoder Lock is active, only CV15 and CV16 can be manipulated When a decoder is locked, all CV values other than CV15 and CV16 will report "Cannot Read CV" or similar on your Command Station.
  • If the values in CV15 and CV16 are different, the decoder is considered locked, and programming request will be ignored.
Decoder Type CV 16 Lock #
Lock Disabled 0
Non-Sound Decoder 1
Sound Decoder 2
Lights-Only Decoder 3
User Defined #1 4
User Defined #2 5
User Defined #3 6
All Locked 7
Decoder Type CV 15 Key #
Unlock All Decoders 0
Unlock Decoder #1 1
Unlock Decoder #2 2
Unlock Decoder #3 3
Unlock Decoder #4 4
Unlock Decoder #5 5
Unlock Decoder #6 6
All Locked 7

Smoke Unit Enable (WOW501)

To enable the smoke unit in the WOW501 program CV58 to a value of 9.

F5 turns on the coil and F6 turns on the fan full blast. These functions must be tied to those specific outputs. F6 is automatic, and does not need to be turned on with your throttle, otherwise the output will turn on full blast until it is turned back "off" to automatic. Those two outputs can also be used as on/off only. Depending on the coil unit you are using, it is recommended to change F5 to a "constant dim" effect which limits the power to the coil. This will extend the life of your coil, and prevent overheating in most cases. The dim generator you select can then be configured to a power level using the corresponding CV. This CV should be set to a level high enough to start producing smoke, but not much more.

[Example: CV55 = 44 CV64 = 1-30 {Your Desired Heat Level - depends on coil itself}]

Speakers - Wiring Multiple

When wiring a multi-speaker arrangement, the resistance of the individual speakers must be observed. TCS amplifiers are rated for 8 Ohms of output impedance at 2 Watts. If you have two 4 Ohm speakers, you must wire them in series. 8 Ohm speakers should also be wired in series unless the total wattage exceeds 2.5 Watts. Alternatively, you can also wire in parallel with a resistor in series, in order to match or exceed the 8 Ohms. Exceeding the load (resistance) rating on the amplifier will not cause stress, but may reduce the maximum volume output. Exceeding the power (wattage) rating of the amplifier will not cause damage to the amplifier.

Note that there are also two high-probability failure conditions for speakers:

  1. Overdriving - If too much current is being passed through a voice coil that it is not rated to handle, it will fail immediately, or over time as the insulation on the wire or physical cone material breaks down. Our amplifiers put out over 2 Watts at full volume when playing loud sounds. Take note of the Wattage rating of your speaker and reduce your master volume as needed.
  2. Heat - When soldering wires to a speaker, it is best to overheat your iron in order to reduce your contact time. If your iron is too cold, it will increase your contact time, and result in more heat transferred into the voice coil and connecting wires. This can break down the insulation, or physically detach or break the wire at/near the pads on the speaker itself. We at TCS run our irons at 720 degrees F or higher to minimize contact time.

Warranty - Decoder Upgrades

WOWSound decoder upgrades are available via our website, which you can go to by following the link below. We charge $25 per decoder plus return shipping, and offer a discount for the more you send in at once.

We do not offer official shopping cart items for non-sound upgrades, but do offer upgrades on non-sound decoders when submitted. The fee for any non-sound upgrade is $16, and can easily be added to your invoice by our staff prior to return shipment.

WOWSound decoder upgrades can be found on our TCS shopping site.

The instructions for submitting a WOWSound decoder upgrade will be in the confirmation email you receive once your order is placed, but to narrow it down, here's what you need to do:

  1. Print the confirmation email with RMA number
  2. Package the returning item(s) in a small box, and also include the RMA form
  3. Send that package to the P.O. Box 341 Blooming Glen, PA 18911 listed on the form as "ATTN Upgrade"

You'll receive updates via email about the status of your return, including when it is received, when it is processed and upgraded, and when it ships. You will also receive a USPS tracking number when we ship.

Warranty Submission Process
For detailed information on submitting a TCS product under warranty, including details on what is covered, please visit our Warranty page.

Multimeter Troubleshooting

NOTE: This section requires the use of a digital or analogue multimeter to perform electrical checks.
NOTE: Continuity checks that include the rails must be performed with one lead connected or touched to the rail.
NOTE: ALL resistance measurements including continuity MUST be performed with the power OFF.

Check resistance/continuity for the following:

  • Left Rail to Right Rail
  • Orange to Grey (motor connected)*
  • Orange to Grey (motor disconnected)**
  • Left Rail to Orange
  • Left Rail to Grey
  • Right Rail to Orange
  • Right Rail to Grey
  • Speaker contacts (speaker disconnected)***

NOTE: NONE of the above tests should read 0 or near-zero.
*Without a decoder connected, resistance measurements of a typical HO-scale motor will read upwards of 200 Ohms, and will vary from manufacturer to manufacturer. Similarly, motors within different model scales will vary, but generally will remain within a certain range. A motor which reads 0 or infinite resistance between its terminals is absolutely bad in all circumstances. Resistance values below 50 Ohms will typically indicate a bad motor, with notable exceptions being "coreless" motors. NOTE: We recommend performing this test while rotating the flywheel. If you see large spikes in resistance upwards or downwards, this indicates poor brush connections or bad brushes, or a failed internal winding. Both of these circumstances can damage a decoder over time as they will often result in spikes of current outside of the maximum safe level.
**With the decoder disconnected from the motor, the resistance between the Orange and Grey wires should be exactly 20K Ohms (with about 100 Ohms tolerance one way or the other). A value in the single-digit KOhms, or MegOhms is unacceptable, and indicates component failure on the decoder.  A value of 0 Ohms is also unacceptable.
***Only applies to SOUND DECODERS - An 8 Ohm speaker itself should read Between 7.2 and 8.8 Ohms. If less than or greater than these numbers, the speaker has failed or is failing and should be replaced.
Check resistance/continuity for the following:

  • Left Rail to (Black) Power Pickup on decoder
  • Right Rail to (Red) Power Pickup on decoder

NOTE: These readings should be near-zero and not fluctuate.
Check DC voltage for the following:

  • Blue wire to ground
  • Orange to Grey (this test must be done with the motor disconnected) Gradually increase the speed step. You should see the DC voltage increase from 0 to ~12V. Reversing direction will also reverse the polarity of this reading.

Check AC voltage for the following:

  • Left Rail to Right Rail

NOTE: Voltage measurements are to be performed with power applied to the engine.


If you have additional questions, please reach out to our Technical Support
team through email or by phone during our open hours. Thanks!
 TCS Technical Support