Joe: If you are able to get a second power truck with a motor, be sure that the two motors are identical. Different motors have different RPM and torque characteristics which would cause problems if they were run together from the same electronics. Williams engines tend to run and start at lower voltages than other engines and if you do have identical motors, you can connect the two in series rather than parallel and lower their starting speed. I recommend this practice on all two motor Williams engines because it greatly improves their performance characteristics. They start more smoothly and still have all the top speed characteristics that you could want.
The way to determine the wiring for two motors is pretty much experimental. Take one of the leads going to the existing motor, connect it to one of the terminals on the new motor and simply connect a wire between the two open terminals on the motors. If the motors are correct, the engine will run just fine in both directions. If the motors are wired backwards, you will see the two motors "fighting" with one turning one direction the other in the other direction and the engine won't go anywhere. If that happens simply reverse the two leads going to one of the motors.
If you are going to use TMCC or DCS on the engine, you might not need to wire the motors in series. I still wire many of my engines with motors in series, simply because it makes for very smooth starts and excellent slow speed performance.
Hope this helps.
Paul Fischer
