debugging my j-2

[blwfish]

I have a Spectrum C&O J-2 (which I assume is based on the USRA Heavy Mountain). Something is wrong with the motor/drive train. I bought it used, and when I got it home, I tested it briefly on straight DC - it was working.  At least, it ran back and forth on my 4' test track.  That was last weekend.

OK, last night, I unplugged the plug and plugged in a known working DCC decoder.  With the decoder, the firebox light comes on, but the engine won't move. If I put it on the DC test track, it doesn't move there either. The decoder had as recently as an hour before been in a different locomotive, so I fried it plugging and unplugging it a couple of times, it should be good.  I think I must have done something to the model, but I can't imagine what. I didn't mess with anything actually in the locomotive itself, which is where the motor and gears are. I just opened up the tender. And since the firebox light (and headlight?) still works, I know that the basic electrical circuits are OK...

I guess I need to break out a voltmeter and be sure that DC voltage is getting to the motor, but assuming that it is, what's the next step?

[jonathan]

I would check the tender/loco connectors to make sure they are seated all the way.  That would be the easy fix.  Sounds more like a loose wire than a decoder problem.  It is possible to pinch those wires when closing up the vandy tender (I assume that's the tender you have).

Just a thought.

Regards,

Jonathan

[blwfish]

Yeah, it sounds like something simple.  I am confident that I didn't pinch the wires closing the tender, because I actually never closed up the tender! I was just letting the decoder sit there on the tender chassis since I wanted to test before proceeding.  The intent was to install a QSI sound decoder, but before I did that I wanted to make sure that I'd done the easy first step of getting a simple DCC decoder installed properly - which obviously I failed to do.

I'm traveling this week, but when I get home I guess I'll try checking the wires again.