This installation is for HO-Scale Athearn Genesis SD-70MAC uses TCS T4X Digital Decoder and was performed by J.F.

Important Soldering Tip:
Please do not use any flux either liquid or paste on the mother board. It will damage it. Use only Rosin core solder approved for electronics use.
We recommend to use only Kester "44" rosin core, SN63PB37, .015" diameter, part number 24-6337-0007.
This can be ordered from Techni-Tool under Techni-Tool part number 488SO157

The Latest SD70MAC by Athearn is a very fine model. It is unique in that it has a built in 1.5 voltage regulator to power all the bulbs. It works for both DC and DCC operation.. Decoder installation is very easy. The loco comes supplied with the 9 pin connector already solder into the lighting board. Remove the jumper circuit board supplied with the loco from the connector and  plug your TCS decoder directly in. See photo below. No soldering required. From the factory the ditch lights are controlled by button one. To allow for alternately blinking operation follow the instructions  below.

There is no need to change bulbs to complete decoder installation.

All the light bulbs supplied with the loco use 1.5v bulbs and are powered from a built in 1.5v regulator on the light board.

From the factory both ditch lights are hooked together and will operate on and off by using button one.

To provide alternately blinking ditch lights, the bulbs must be separated at the point marked F1_N and F1_P. See enlarged photo of circuit board above.

One bulb then needs to be hooked to the terminals marked F2_N and F2_P or the holes marked 2X and 2Y. The other bulb remains connected to F1_N and F2_P.

Use the T4X or  T6X decoder as they support Blinking Ditch lights.  All X series decoders have improved ditch light operation by allowing more

Change these CVs to set up your TCS decoder for alternately blinking Ditch lights.




Use button one to control on/off of Ditch Lights and button two or five to activate blinking.  You can select which button activates the blinking by changing the value in CV124. refer to table 19 in your decoder literature.

Other solder tips: When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire

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