generator will not crank 1983 newell

[champcar50]

About three weeks ago we used our newell and all was good with the generator. I shut it down when we arrived home checked all fluids and all was well. This past weekend we were all packed for a trip started the bus and flipped the switch to start the generator and nothing. so no trip. I used a test light and verified 12 volts at the main post on the starter solonoid but no voltage to the start terminal. When I shorted between the start terminal on the solonoid and the main battery wire on the solonoid the generator cranked and only ran while cranking. I see no fuses on my fuse schematic for the generator so I kept looking. Above the fuse panel is a circuit breaker with five wires when I flipped it on to reset, the generator started and ran. this circuit breaker tripped again and I believe I need to replace it. It is an AIRPAX part #APGN1-1REC2-6153-1. on thier website it says a 30 day wait while they make one. Does any one have any idea why this thing has five wires on separate terminals on it. Exacty what is its purpose. Any ideas where I might find one or is there some way to substitute another circuit breaker for it
Our newell is a 1983 with the 12.5 kohler genset. I have no idea where the control box I have read about on here is located. A wiring schmeatic would sure be nice. Any help / suggestions appreciated.
Thanks
Jack Ball