Three Truck Shay trouble shooting

[Rex in Pinetop]

I have a Spectrum 3 Truck Shay.  I converted it to battery power with Airwire control.  It has been running fine for two seasons until today.  The middle truck stopped.  The front and rear trucks are running.  I opened it up and checked my wiring.  The front and middle trucks have orange and green motor wires and are connected to the same decoder board terminals.  The front truck is running fine but the middle truck has stopped.  I reconnected the wires to confirm a good contact with negative results. 

My question:  How do a trouble shoot the middle truck's motor?  If it's bad how do I replace it?  I can't figure out how the trucks are connected to the chassis/tender.

Thanks for your help,

Rex

[Loco Bill Canelos]

You can check the motor in the truck to insure it is not the problem by disconnecting the motor leads and connecting them directly to a dc transformer and applying power to see if the problem is the motor. If the motor is not the problem then it must be in the wiring connection in some way.  Since the other trucks run fine, it would seem that the airwire is not the problem or they would be dead as well.  if the motor does not run check all the internal wiring in the truck with special attention to the two wires that go to the motor.

Best I can do for now, hopefully someone else will chime in with better advice since I do not have airwire.

Bill