I realize this thread is ten years old but I recently purchased a used DC MT4 off ebay and while it appears to run the trailing truck under the cab is causing a short unless it's running on it's rim/not making contact with the track despite it not being supposed to draw power. I'm trying to see if I can insulate the trailing wheels somehow with traction tire(s) but this may be a potential cause for OP's issues as well
Trevor,
I tried to come up with something, but didn't. If no one can help you out, in case you don't have it, here's Athearn's help info:
http://www.athearn.com/Support/Default.aspx
Cheers,
Frank
Edit: To The Forums.
Hello Everyone,
I have an Athearn Genesis MT4 that ran great up until 3 weeks ago, however something got jammed in the mechanism (or so we think) and it now will not move. I sent it to a friend of mine who is a master modeler in the narrow and standard gauge world and he couldn't figure it out after tinkering with it and the exploded parts view. I was wondering if anyone here has taken one of them apart, and if so do you have a description or pictures of how it comes apart. It would be much appreciated.
Trevor