trolley power issues

[godfather55v]

I have a trolley on a auto reversing track that i put up as part of a christmas display.  The trolley's power is cutting out, even w/ the controller on high.  The trolley will go a ways and as it's going i can see the head light  bright and dim as it chugs along.  The track is all tight, what else can i check?

Many Thanks!

[spookshow]

Cleaning the wheels and the track is always a good place to start.

-Mark