Unfortunately it is also demonstrating the typical mechanical condition of tired shortline mechanical power. I've made several repairs, but I'm stumped on this latest problem. Can anyone who has worked on one of these models give me some advice on where the problem might be?At first the B-unit would run but the A-unit would not. I disconnected the drawbar between them, dropped the trucks from the A-unit and bent the wipers back so they would make proper contact and reconnected the trucks. I test ran both the A-unit and the B-unit separately and they worked fine. I reconnected the drawbar and test ran them again. Within 30 seconds the B-unit slipped the front motor pinion. I once again disconnected the drawbar between the units and in short order had the motor removed and the pinion back on the armature. I reassembled it and put it back on the track, only to find that it is now shorting out somewhere.
I've pulled the motor, checked it with a meter, pulled the contact plate for the motor, checked it with a meter; both read an acceptable level of resistance (definitely not the source of the short). I put the frame and trucks on the track without the motor or contact plate or driveshafts and it is still a dead short between the rails. I'm at a loss to explain what the heck is going on. Can anyone point me in the right direction? At this point I'm not opposed to leaving the drive train out of the B-unit and running it as a dummy but it can't be a dead short across the rails.