This installation is for an HO-Scale Bachmann EMD GP40 using a TCS WOW121 Diesel Decoder, AK-MB1 Motherboard with built in Keep Alive® by TCS.
HO-Scale train Bachmann EMD GP40 prior to installation.
To start off this install, we must first remove the two screws highlighted above in red on the bottom of the fuel tank.
Next, we must remove the two screws highlighted above in red found under the fuel tank on each side of the speaker. With the screws all removed, lift the shell off of the frame. Take care with the handrails as you lift off the shell so they don't break.
The Bachmann EMD GP40 shown with the shell off.
Remove the two screws highlighted above in red, unplug and remove the wires from the original decoder board and remove it from the chassis.
Shown with the original decoder board removed. Trim and tin, or lengthen the wires as necessary.
Using clippers, remove the front LED from the original decoder board as shown above as highlighted in red. Save this LED along with the original rear LED for reuse.
In the opening located on top of the frame, locate and remove the yellow cap highlighted above in red, clipping it from the motor. This will not be needed.
Using double sided foam tape, attach the AK-MB1 motherboard to the frame and solder the motor and track pickup lead wires to it according to your included wiring diagram.
Using a dab of hot melt glue, reinstall the front LED base onto the frame in front of the AK-MB1 as shown above.
Mount the front LED to the base using hot melt glue. Insert the rear LED back into it's holder and then solder these leads to the AK-MB1 according to the included wiring diagram. TCS motherboards include on board current limit resistors for LED use. There is no need to apply external resistors for LED use.
Solder the existing speaker leads to the AK-MB1 and you can then plug in your WOW121 decoder. While making sure the speaker is secure in the frame, reattach the shell with the original screws into the frame. Replace the original fuel tank with the saved screws and your Bachmann EMD GP40 is now WOWSound equipped and ready to roll!
Important Soldering Tip
Please do not use any flux either liquid or paste on the mother board. Over time, the acidic properties of liquid or paste flux will begin eating away at the fiberglass PCB and will damage it. Use only Rosin-core solder or no-clean flux approved for electronics use.
TCS recommends the use of Kester "44" Sn63 Pb37, .015" diameter Rosin-core solder. Kester part number 24-6337-0007.
You can order this solder from the following retailers:
Digikey - PN:KE1110-ND
Techni-Tool - PN:488SO6775
Other solder tips
When stripping wire, only strip a tiny little bit of the insulation. Strip no more than a 1/32 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire than 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