Im new to this board and have a questions regarding my son's new chirstmas train set.  We got th Big Hauler Night Before Xmas set (90037) and been having a little problem with it.

I set it and it ran fine when we first got the set a month again.  Now it setting it up for the second time and after the engine is on the tracks and runs for about 10 seconds it stops and shorts the control box.  Once I take the engine off the tracks, the indicator light on the control box lights up.

Not sure if the problem is the engine or the control box.  Any suggestions would be helpful

thanks