PM a railroader's engine.
First time 'working' on a Bachmann steam engine.
A 4-8-2 engine.
The engine would run and then, periodically, loose power.
Found out that the engine drivers do not provide any electrical contact for the decoder.
The tender trucks are the only means of providing power to the decoder.
The two sets of brass contacts were not, consistently, conduction electricity as the sound would stop when moving the tender from one side of the track to the other side.
Removed one wheel set and the brass contact came off. Friction makes contact to the center bolster as well as to the axles.
Cleaned the center and ends of the contact plus bent the contacts 'down ward' to get more pressure on the center bolster and axles which remedied the problem.
The back set of wheels on the front truck was not rotating.
Had to file some of the plastic off the 'arm' that connected the truck to the frame.
