Decoder wire lengths:
Black = 4-1/8 inches Red = 3-3/8 inches White = 3-3/8 inches
Blue = 3-1/8 inches Gray = 2-3/8 inches Orange = 2-3/8 inches
Yellow = not used
It's always been my practice to never solder the motor wires from the decoder to the motor brush caps while they were installed on the motor. Normally with all other installs, I remove the brush, spring, and caps. Then solder the wires to the caps and then re-install everything into the motor. On all other loco's I've worked on this works out fine as the caps or brush holders snap into the motor body. On these ConCor locos the motor brush mount screws into the motor. With the wires already attached, the wires end up getting very twisted.
The motor brush contacts point away from the top part of the frame. When assembled, they made contact with the lower parts of the frame assembly.
So my method for the ConCor cab diesels is this: I first fully unscrew the mounts and remove them. Then place a small amount of solder on the surface of the mount. After it has cooled, I re-install the brush, spring, and the fiber washer and screw the assembly back into the motor with contact part not used. I don't fully tighten it but leave it loose about 1/2 turn. Then I solder the tinned motor wire to the spot where the solder is. The fact that the mount is a little loose, the fiber washer, and the solder already being on the mount seem to keep the mount from getting hot enough to melt the plastic of the motor. The angle of the wire needs to be pointed upward as shown in the photo below.
When the motor is re-installed into the milled top part of the frame, the motor wires go up through the slots that are milled. This view is of the left side of the mechanism with the mechanism upside down.
I have found that the trucks can short on the frame so I add short lengths cut from .010 x .125 strip polystyrene to the areas of the trucks shown in this photo. The polystyrene strip is held in place with Tap Plastics E6000 adhesive.
On the red wire I used a motor brush contact from a Kato motor to attach the red wire.
On the black wire because the screw is so close to the top part of the frame I did not use any ring. Instead I just made a loop at the end of the black wire.
Place the heat shrink over the wires and solder the resistor to the lead with the smaller element. Then attach the blue wire to the resistor and the white wires to the lead of the larger element.
The model origionally came with black electrical tape over the headlight area to keep the light from shining unrealistically in the cab windows.
I did not see a better way to do it so I did the same thing. The front edge of the tape should be even with the front edge of the top frame and the LED.
The fuel tank clips into the shell at two spots on each side and that is what keeps the shell on.
The light should come out brightly on the top large headlight and more dimly on the bottom headlight and the number boards similar to this photo.