I'm a new member here. I'm also brand new to O-scale stuff and especially to A/C based trains. I never had a Lionel layout of my own when I was a kid, just HO and all D/C based.
Anyway, I've bought a bunch of stuff over the last few months and one thing I got was an old 70's era (as far as I can tell) basket case diesel engine. One truck has the motor and the other side of the diesel has the reversing solenoid. When I put the engine on the track, the lights turn on on the engine but the reversing unit buzzes like crazy like its going up and down constantly and the drive motor does nothing. The wiring on it looks like someone before me at one time attempted to try to get it working and was unsuccessful. The wires are twisted onto the solder tabs and so on. Totally amateur repairs. I'm assuming that the buzzing is because the solenoid is wired to two pre-transformer wires instead of post. I'm not really sure, I'm used to A/C being converted to D/C via a rectifer but not sure how it plays into these engines.
I'm good at wiring and soldering and following diagrams. Can someone point me in the right direction?