I have a Polar Express Engine in S Gauge by Lionel. When I started to run the engine it runs intermittently. It will go for a few sections of track then stop, shut down, restart and go again. I am using Lionel FastTrak around my Christmas tree.
I can run the engine on my main layout and wit works until you go slow and then it acts ups. I have cleaned the pickup wheels and the track. No success. It is almost like having a broken wire that makes and brakes contact. I have not run this engine much as it is part of my Christmas tradition. I t has less than 50 hours of run time.
Does anyone have a suggestion to correct the problem.
When running, the engine produces all the correct sounds, bell, and whistle.

David

Appears that you were right. The small circle of track around my Christmas tree was not making connections. The main problem was the wall wort connection to the track. While the light showed it was powered, The power was not getting to the track.
Thanks for the info.