This installation is for Athearn GP40-2 uses TCS MC2 decoder and was performed by A.G.
Shown with the shell on, prior to decoder installation.
Front of the locomotive.
Back of the locomotive.
Grasping the shell by the solid area between the grills, lift the shell straight up and off of the chassis.
Remove the copper bar that supplies voltage to the bulb.
Remove four circled in red screws so that the motor can be removed from the chassis.
Here is the picture of the motor that was removed from the frame.
Use some electrical tape to Isolate the chassis from the motor as marked in red in the picture above.
Solder the orange wire of the decoder harness to the bottom copper tab of the motor. Isolate the solder point and reattach the motor to the chassis.
Solder the gray wire of the decoder's harness to the top copper tab of the motor as shown in the picture above. Isolate the connection with an electrical tape.
Solder the red decoder's harness wire to the front power pick-up tab (as shown in the picture above).
Solder the black decoder's harness wire to the front power pick-up tab as shown in the picture above.
There was no voltage specifications for the Bulb that was originally used in the locomotive so we decided to use LED. The 680 Ohm resistor was placed and all the installation was isolated. Use the white and blue decoder's harness wires to connect the light.
Here is the picture of finnished TCS MC2 decoder installation.
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