I am not a train person, I bought a used Trim A Train N scale. I a getting voltage to the track. The engine is not running. Questions: should the wheels turn freely on the engine without power simply holding it in your hand? Anyone have a manual on the train/engine? The engine is connected to the next car via  a plastic post of some kind, it seems to move in and out,,, what does this do? I only paid $25, but I wanted it to work, and of course told that it did. Any help will be appreciated. Thanks..