Onan

[wshelton]

Back to an existing problem. A short while ago I posted a thread about my 7.5 diesel Onan and got some good answers although by happenstance I solved the problem, albeit temporary.

Foe those of you who recall my start switch would not turn the motor over and the Amp meter was pegged into the negative mark. I took the fuse out to check it and replaced it and the amp meter righted itself and I monkeyed with the solenoid and the dude fired off okay. I thought issue solved. Generator ran fine this weekend however would not turn over this AM so back into the sauna for another look.

Here is the deal. This solenoid is not pushed in which will allow motor to run. I can hold it in and the motor will run. I know this is not good. Now the funny thing.

While trying to start the motor if I push in the red reset button and hold it in the motor will run fine. The solenoid is in correct position too. If I release the reset button the motor cuts off, solenoid pushes out.

Never had this problem before. Do I replace reset button? or solenoid or both. Why does the amp meter peg down into the negative reading while the genset just sits there? Push reset button and meter goes back to proper reading, however in a few minutes this deal will hammer down into negative territory again.

I have now turned battery switch off and come home. Your assistance please once again.

Will Shelton

 

[Bob Bradley]

I chased spooks in that damn box for years. There's no diagram, and the wires are all the same color. I even traced the wiring and drew up my own rudimentaty wiring diagram. It still drove me nuts. Even when I jumpered out most of the connections with toggle switches, it still only worked imtermittantly. Last summer a nice new Norpro solved the problem permanently.

 

[rsmith]

Back to an existing problem. A short while ago I posted a thread about my 7.5 diesel Onan and got some good answers although by happenstance I solved the problem, albeit temporary.

Foe those of you who recall my start switch would not turn the motor over and the Amp meter was pegged into the negative mark. I took the fuse out to check it and replaced it and the amp meter righted itself and I monkeyed with the solenoid and the dude fired off okay. I thought issue solved. Generator ran fine this weekend however would not turn over this AM so back into the sauna for another look.

Here is the deal. This solenoid is not pushed in which will allow motor to run. I can hold it in and the motor will run. I know this is not good. Now the funny thing.

While trying to start the motor if I push in the red reset button and hold it in the motor will run fine. The solenoid is in correct position too. If I release the reset button the motor cuts off, solenoid pushes out.

Never had this problem before. Do I replace reset button? or solenoid or both. Why does the amp meter peg down into the negative reading while the genset just sits there? Push reset button and meter goes back to proper reading, however in a few minutes this deal will hammer down into negative territory again.

I have now turned battery switch off and come home. Your assistance please once again.

Will Shelton

bad ground somewhere the red button pops on overheat or lo oil probably a wire broken off or bad sensor. buts its a OH-NO so it could be anything. I asume its a mdjb?

 

[34Hatt]

Sounds like the Solenoid is bad drawing high current which is popping the breaker. They are know for going bad and cost some $$$ from Onan.

Someone here posted finding it somewhere else for much less.
Maybe try a search it could save you some $$$$

 

[Nonchalant1]

The red reset button is not a "circuit breaker" for the solenoid in the sense that it does not pop from over drawing amps. It is a breaker in that it breaks the current to the fuel solenoid when the reset button get current to it's coil from the sensors. It is a time delay breaker because it has to heat up an internal coil until it pops the plunger with a spring. If the reset button is shot, it will not reset and will keep the engine shut down. I would bypass the reset button and run the genny briefly. When it's running, check to see if there's positive current in the wire that goes to the reset button inside the control box. If there is, the reset is beiung tripped by a faulty sensor. If there is no current, then the reset button is faulty and needs to be replaced. The reset button pushes in and makes a click and stays in a little when it is reset after tripping. If yours doesn't click, that's another likely clue to a bad reset button.

Doug

 

[34Hatt]

The red reset button is not a "circuit breaker" for the solenoid in the sense that it does not pop from over drawing amps. It is a breaker in that it breaks the current to the fuel solenoid when the reset button get current to it's coil from the sensors. It is a time delay breaker because it has to heat up an internal coil until it pops the plunger with a spring. If the reset button is shot, it will not reset and will keep the engine shut down. I would bypass the reset button and run the genny briefly. When it's running, check to see if there's positive current in the wire that goes to the reset button inside the control box. If there is, the reset is beiung tripped by a faulty sensor. If there is no current, then the reset button is faulty and needs to be replaced. The reset button pushes in and makes a click and stays in a little when it is reset after tripping. If yours doesn't click, that's another likely clue to a bad reset button.

Doug

That makes some sense but he said Amp meter pegged and the solenoid tried to engage but just did not fully engage at least that's how I read it.