I am new to the forum, and have searched, but not found a thread dealing with this problem so here goes. We have a 1980 Mainship 34, Sirius,with an Onan 3MDJA generator. The last time the generator ran it was on light load (the battery charger) for about 10 minutes, then the decompression solenoid de-energised and it stopped.
So far I have checked the cooling system in case it was an overheat, all clear. Have checked the high air, high water temperature cut outs, and the oil pressure switch, all good. I have inspected the brushes and they all look good to me. Trying to start it, the oil pressure switch closes, the decompression solenoid energises, the engine fires, but stops when the start switch is released, because the decompression solenoid de-energises.
I found the engine would run if I jumped across the current reversal (charge) relay. The jumper keeps the solenoid energised from the battery rather than the generator (while the generator is running), but there is no output from the generator, 12 volt or 120 volt.
Can anyone identify the problem, and its possible solution? Any help much appreciated.
So far I have checked the cooling system in case it was an overheat, all clear. Have checked the high air, high water temperature cut outs, and the oil pressure switch, all good. I have inspected the brushes and they all look good to me. Trying to start it, the oil pressure switch closes, the decompression solenoid energises, the engine fires, but stops when the start switch is released, because the decompression solenoid de-energises.
I found the engine would run if I jumped across the current reversal (charge) relay. The jumper keeps the solenoid energised from the battery rather than the generator (while the generator is running), but there is no output from the generator, 12 volt or 120 volt.
Can anyone identify the problem, and its possible solution? Any help much appreciated.