Burnt wiring question

[Fred Bear]

Wow, what a lead in for a question, I mean, what could one really ask?

But here it is. My MTH Shay derailed, I saw a bit of smoke, and now it shorts the transformer. ( No, I did not have a quick blow fuse in line on the ZW, I do know, just a bit late ). I called MTH, the guy said look for burnt wires, red & black. I found them, all melted together. I fixed them but the thing still shorts out. Could there be more? What about in the tender? Any way to check the circuit to find out where this baby is shorted? Thanks much, Jake

[eZAK]

Jake,

Will the ZW work w/o the engine on the track?

If you are sure the short is in the engine, re-check all wires including the tender. You could try a continuity testor on various wire runs if they are disconected at each end. Leaving them connected to the electronic boards may result in false readings. Another area to check is the boards themselves for any burnt marks or popped components.

For future info. a cheap TVS ( http://en.wikipedia.org/wiki/Transient_voltage_suppressor_diode ) would have saved your engine.

[Fred Bear]

The guy at MTH sugggested a 15 amp, 32 volt, quick blow fuse in line on the hot side before the TIU. I placed on in there now, but kinda like closing the door after the horse gets out.

I'm going to call MTH again, I have the engine completely apart now, I cannot see any other problem areas, but something is wrong. When I replaced the burnt wires and set the engine back on the track, it blew the 15 amp inline fuse I had just installed, so whatever is tripping it is pretty messed up I'd say.

After taking the two leads of both rollers, and attaching a hot lead and ground/neutral to those terminals, it did not create a short, but...that's disassembled and off the track, with the engine just lying there on its side, apart.  Thanks for any advice, Jake