Dash-8 Contact Problem

If you don't find anything loose, check for a cold solder joint somewhere. Little Chinese girls have Monday mornings just like anybody else, and I've fixed plenty of problems of that nature with a quick touch from a soldering pencil. 

 

That said, I suspect you'll find something obviously loose when you examine it closely. Sometimes the wire ends are not properly secured in the female plugs, resulting in bad connections. 

Now that Mr. Hiawatha has shown his ignorance, you'll be pleased to know that this piece was made in the US.

 

Having said that, there aren't any known issues with those locomotives, and the power-truck assembly is based upon one in use for ages. The lights in that locomotive are wired directly to the track without passing through any electronics, so if the locomotive is completely dead and dark, that's a big clue that it's not getting any power at all.

 

This locomotive's electrical system was assembled with wire nuts, and they can be a source of problems. The center rail rollers should be wired to one, and ground comes from one of the lugs on each motor. Find those particular two wire nuts (there will be a bunch of wires in each one for the lights, reversing unit, MARS light board for the roof light, etc.) and that's where I'd start finding where the problem could be.

 

I hope this helps.

TRW 

Thanks for the suggestions, TRW; one thing I can't figure out is why, with the cab off, if I press on the FRAME next to the truck, it goes until my finger comes off.  I already re tightened the wire nuts but didn't do a tug test on em yet.

TRW - Even if the unit was assembled in the USA, the electronics are imported - and that's where you look for cold solder joints. The wire nuts are an excellent place to look; the wires can be disconnected inside even if they appear to be connected. Sometimes the bare portion of the wire is too short and it helps to strip the insulation off a bit more of the wire when reassembling. 

Carl,

 

This can be a difficult thing to diagnose remotely, and I'm not sure why you can get it to work when pressing on the frame near one of the motor trucks.

 

Each truck is identical in that both pick-up center rail and ground, and therefore there's a redundancy where one truck can supply power even when there's a problem with the other. That's why I suggested starting with the wire nuts, as it's where everything comes together.

 

TRW 

Wrong again.

TRW