Power and torque loss on EMD GP40

[gb]

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

[ACY]

It is possible the loco is overheating, due to being damaged. Also, the chances your track is adequately clean are probably slim, clean the track well with a track eraser or cleaning fluid and a non-fibrous cloth.

[jward]

did you mean that after a couple of minutes, the power shuts off completely? when the locomotive doesn't run, are you still getting power to the rails?

the fact that after things have a chance to cool down, you hear an audible click in the power pack leads me to believe something is tripping the circuit breaker. the question is, is it internal to the power pack? in that case you'd need to replace it. or is it something having to do with the locomotive? if  you have a hobby shop or friend who has trains, you can have them run the locomotive on their system to see if it works properly. the third possibility is that there's something wrong with the track and/or wiring. disconnect the track from the power pack, remove the locomotive from the rails, and checque the rails with an ohm meter. you should get a very high number of ohms when measuring resistance between the rails, low resistance when measuring along the same rail.

to me what it sounds like is something heating up and tripping the circuit breaker in the power pack. the above should help you narrow down the problem.