This installation of TCS T1 Decoder is for HO Scale Hobbytown GP7 and was performed by Jean Lacroix, Canada
This model is a Hobbytown of Boston drive with a body shell from Athearn. On this model, the body is attached to the frame with two tabs located on each side in the middle of the fuel tank. You just have to push out the skirt of the locomotive body in order to remove it. Normally, it is not necessary to remove the couplers.
All the wires connected to the motor should be removed from it. The motor is attached directly to the frame which will create headaches since it is not insulated from it. To solve that, the motor has to be isolated. The motor has to be unscrewed from its location since it could create an electrical short, especially in dcc mode. To prevent that, install on the floor of the locomotive, where the motor was, a rubber pad or a piece of plastic large enough to isolate the motor from the frame. The motor should be glued in place using Goo or silicone, taking care to avoid any moving parts. Pay special attention to align the drive shaft and the motor sprocket.
The orange and grey wire from the T1 harness should be soldered to the contact located on each side of the motor. Then connect the red wire to the top of the front truck. In the next step, connect the black wire to the frame. On this unit, you should install extra contacts using phosphor bronze wires inserted in plastic tubing on each truck, in order to have better electrical pick up current from the track. This is done on the side of the locomotive that has the wheels insulated.
In order to offer a good place for the decoder, a plastic platform was added on top of the driveshaft. Installing the decoder on the platform has the advantage to prohibit wires to get entangled around moving parts of the drive train. You now have to reinstall the body.