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@Train Nut posted:

Thanks for the input. So where does the ground in the middle of the tube go to?   Does it ground at some point to the wheels? Shouldnt I have continuity from the shoe through the coil to the wheels?

The accessory shoe rails on the uncoupling track are energized with center rail power when the uncouple button is pushed. This power goes through the rivet in the accessory shoe. The top of the rivet is contacted with a copper spring which conducts power to to the fiber plate on the rear of the coupler. One end of the coil wire is wrapped around this spring. The return path varies a little depending on the type of truck.  The coil wire is wrapped up between the coil and the tube it is wrapped around. That tube contacts the coupler body. The coupler body is crimped to a plate that hangs on the axles. Wheels on the axles contact the outside rail. There are lots of contact points that might be a problem.  I would use a wire to probe the various joints to see where conductivity is being lost.

The coil wire where your red arrow is pointing needs to be connected to a metal part of the truck. (Make sure the insulation is scraped off the wire for it to make electrical contact.) Touching power from the transformer to the pickup shoe (or the solder lug next to your red arrow) and the metal of the truck should activate the coil and open the coupler.


If you turn the truck over you will see where the coupler is crimped to the plate that is attached to the axle. That  silver disc is just a good place to get good contact to the coupler body. The crimp between the coupler and the bottom plate is one place you can loose the ground contact.

Sounds like we're talking this area here.20201028_104014

So the unvarnished end of the wire Just sandwiched between the metal? If so, I imagine drilling the rivet out and trying to make a better connection is the fix?  Unless of course the coil is bad.


Images (1)
  • 20201028_104014

Ok Larry, I feel stupid.....

I should just tried the transformer to begin with.....    They both work! 

I was too lazy to get the transformer and used the meter and it bit me!  LOL

I'm still stumped why the meter showed no continuity from the lug to the frame though. 

But the good thing is they both work. 

Thanks Larry and thers for the help!


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