Anyone know when the light on the coal cars comes on. Does it have to have the 9 volt battery installed to light it up.

I have nickel track and brass track. I can not get my G scale track to run around the track. Runs pauses, runs again pauses, then just stops. I put the loco on my bench and hook it up with a piece of track and loco runs fine. So you would think it is the front truck pickup causing this. I have cleaned cleaned and cleaned, still does the same thing. I went and bought some brass shim stock that drags on the track, guess what, does the same exact thing. The loco can not pickup power off of this track. I am wits end as to what to do. Train used to work just fine. Its like there is a magic coating that I can see on the rail. I went and lightly used Emory cloth to run around the track with.

Has anyone had this problem, does it with the brass rail also. I had a second loco that I tripped over and broke it and it did the same thing when it worked. Seems to be all track related. I am stumped. Please help