Greetings,
Newbie here. My three year old son was given a Bachmann set containing a GP40. I immediately put it away after there was too much Godzilla and not enough proper Bachmann. Well, it came out again and so our track and train has suffered some abuse. After I checked it out and replaced wheels and couplers, I got it working safely out of site and have discovered the following symptoms:

I was testing climb capability and was enjoying the power and slippage. After a while, the reverse polarity fizzled down to a 75% torque/power loss. The track was confirmed to be functioning correctly.

Now, after a couple minutes of run-time, the train will suddenly lose current. I turn the control off. After a minute or two, the control box will make an audible click. Then the train will usually work again.

I think maybe a wiring issue? Thanks for your help! -g