PW 681 Question Again

Bruce-

There might be a wire getting pinched when you put the shell back on the frame, or you could have a wire with cracking insulation. I'd also look to see if any of the exposed connections are touching the shell too, creating the unintentional ground.

-John

John

Its doing it without the body, I don't see any problem with the wiring but I'm sure, its all original wiring and my old eyes arent what they used to be

Being a Magne-traction engine, look carefully at the pick-up assembly that the wheels have not picked up a screw. 

Chuck has good advice. More often than I would admit, a freshly serviced loco would short out when put on the track and powered up. Staples and small screws play havoc with careful servicing. 

Dr Tinker had trouble with a Turbine once, ran fine without the boiler, not with it. Turned out the frame had been bent.

I did look but will check again in the morning.  That was my first thought, must be something really tiny and in a place hard to see.

I had this same problem with my 681 and I found that the felt washer that seals the smoke unit between the smoke unit stack and the body was missing.  The smoke unit wire that exits at the top of the smoke unit was a little frayed and bare and was shorting against the metal body.

check the wire to the pickup, when I first got my 671, the pickup wire was frayed and shorted to the frame.

As David wrote, the wire to the smoke unit heater is a likely candidate. Also check the wire to the light socket, and the power terminal on the e-unit. Any of them could be shorting against the body.

If it is doing it without the shell, you need to look at pickup wire touching ground at some point, smoke wire, or light as mentioned.

Any binding of the motor?  Did you mess with motor leads?  G

Ooops.. I misread the original post, I thought the short was only present with the body on.
I would still check the smoke unit and light bulb wiring.

I would also check the collector terminal (as another already wrote).

Also, take a look at the e-unit. I had one loco with a short that turned out to be caused by the e-unit drum. The problem was not obvious with a quick look. One of the nipples was broken off, and the e-unit drum twisted out of position, causing a short.