Engine's symptom- changes direction on its own while running down the rails
I am repairing a Lionel 2-4-2 starter set steam engine. It has a two position reverse unit. I did all the normal service to it, cleaned wheels and pickup rollers, cleaned commutator, replaced brushes. When the engine is connected via alligator clips the engine runs fine, when it is on the rails the engine's issue returns, and I have tried cleaning the track .
any ideas? I am stumped. It can't be the e unit, when it is not on rail it runs fine, I did notice in reverse the engine will not change on its own. Only when traveling forward?
has anyone come across this?