Onan 4000 Intermittent Generation

[Metalman]

The generator starts and runs well. However sometimes it will not produce any power. If I shut it down and wait for a while then restart it, often it will produce power as it should. I have turned the circuit breaker on the engine off and on and then sometimes the generator will produce power. There is no discernible "click" when the handle of the lever is moved. There is very little resistance to movement when the lever is moved. Not at all like a circuit breaker in a house. I wonder if others have the same situation where the breaker lever doesn't make a click when moving from on to off or off to on?

[16ACE27]

I just checked mine for you. It's a soft breaker with a soft click - nowhere near what you'd get in a house breaker.

The good news is: the generator is producing voltage at the proper frequency - otherwise it would shut down with an error code.

Have you checked your ATS connections? Common loose wirenut problem. I'd get in there and check that and then put a voltmeter on the generator side and see what you get.

It's under the L-couch behind and to the outside of the power center.

[Metalman]

Thanks for the quick response. I recall several years ago when I was doing something under the dinette bench seat I saw and then tightened two loose connections on some device. I will check again. The odd thing is that the problem is intermittent.

[16ACE27]

Originally Posted by Metalman

Thanks for the quick response. I recall several years ago when I was doing something under the dinette bench seat I saw and then tightened two loose connections on some device. I will check again. The odd thing is that the problem is intermittent.

That's what happens with poor connections. Sometimes they work; sometimes they don't. Sometimes they heat up and cause a fire.

[TheDustyGeek]

This is one of those cases where a multimeter is key. Set it to AC, test to see if it’s providing power to the wires leaving the generator, and follow the wires/test at each junction until it reaches your breaker panel. It may be possible that there’s a wire nut in one of those junctions that wasn’t assembled properly and it has worked loose enough so it’s only intermittently making contact.

I think we can rule out the wires between your transfer switch and breaker panel, though, since you don’t report any issues when on shore power.

The point about fire above is important. If it is only intermittently making contact somewhere, it’s probably not making GOOD contact when it does, which means it’s generating excess heat which could catch something else on fire.

It’s also possible that the contractors within your transfer switch scored and not reliably making contact, possibly from regularly transferring between AC and generator with a high load applied (e.g., air conditioner running). If this is the case, search on YouTube for a channel called ‘My RV Works’. He’s an RV tech in Washington state and I recall he did a pretty in-depth troubleshooting video on a transfer switch at some point.