Large Christmas train runs for short time and stops

[Bach]

After train stops it can be left for a while and then it will work again.  Is it overheating?

[Mark Oles]

Sounds like something is resetting itself. 
I suspect the transformer may be the culprit.  Is it getting warm?  I think the current Bachmann transformer is a big block wall plug running to a controller.  Check the wall plug for heat.  Unfortunately, the power supply that comes with the sets seems to have a voltage leakage, even when it is turned all the way to "0".  I'm not sure how long they last.   You might consider getting a new power supply if you can't figure out what is causing your set to stop. 

1. When the locomotive stops, do the lights stay on? 
2. If the answer to #1 is "no", Turn the locomotive over.  Are the wires at the lead truck still connected?  Perhaps one of the leads is coming off. I gave a Tweetsie set to my brother and that apparently happened.
3. If it is neither of those, perhaps it is the power supply.

[altterrain]

If you have a Big Hauler train set, its most likely the transformer (power supply) is overheating. They are known to do this. LGB/Bridgewerks makes a 3 amp and Crest/AristoCraft makes a 3.5 amp power supply that would make a good replacement. There are numerous larger power supplies available too.

-Brian