Hi! I have a 2013 class C with an onan 4KY generator (series P). It only has about 200 hours on it. It shut down one day (actually after being on only for about an hour after Hurricane Ian) and then when starting, it turns over great, but shuts down right after releasing the start button. When I hold the button, I get a four blinking light code.I disconnected the inside switch with no luck.The odd thing is that, about 2 months later, I tried starting it, and it started right up and ran (no load) for 5 minutes and I manually shut it off. I tried again a couple of weeks later, and it started right up again. I tried last week, and back to the issue of shutting down right after releasing the start button.It is a manual transfer, so I have a 30 amp outlet I plug my RV cord into when I want to use the generator. I checked for AC voltage at this plug and get about 20 VAC. Any thoughts? I initially thought brushes, but having it start up in between issues seems like it might not be (and also the low hours).The RV is a bit low on fuel (about 1/4 tank) but I would think that a low fuel situation would not fire the generator to run initially anyway. (Unless there is some sort of electronic fuel sensor on the genset that faults the control board?? - I always thought the fuel pick up was just higher in the tank). The control board it buried under the start relay, and I haven't tried taking out P1 and looking into that yet. Any thoughts on accessing the control board on this model? I'm trying not to have to figure out how to get the generator out of the RV and work on it while still mounted.I don't believe there is any oil sensor (the oil is full - recently changed about 20 run hours ago), but if you believe otherwise, please let me know!!Thanks in advance for any insights or help.

So it doesn’t run and when it does, it doesn’t put out 120v? Problems are likely not related.

Ok after it shuts sown the light wil blink IN A PATTERNYou can also start the pattern by tapping the stop button as I recallWhat is the pattern Like 3-4-2 3-4-2 3-4-2 as an exampleNOTE this translates to what the on-board computer THINKS the problem is but the computer is not all that smart.Some things that can cause itLow oil OR lOW OIL PRESSURE.. The sensors are offline during startNO AC OUT Likewise. Sensor offline during start (That last can be major)Several other issues.

Ours will do that also IF either the oil level is low or the gas tank is not nearly full.Since becoming aware of those issues and keeping things topped off, I’ve had no problems.Bob

Did you prime the generator before trying to start it.It sometimes takes a few times to get enough fuel to start the engine.By the way, you should always run the generator about an hour to dry out all components. There is a saying for generators: "Use it or lose it.".

When I had an ONAN in my previous MH, the ONAN manual said to exercise it for 2 hours once a month under 50% load.

Onan generator shutting down after releasing start button

Grit_dog
Navigator
Mar 04, 2023
So it doesn’t run and when it does, it doesn’t put out 120v?
Problems are likely not related.
wa8yxm
Explorer III
Mar 04, 2023
Ok after it shuts sown the light wil blink IN A PATTERN

You can also start the pattern by tapping the stop button as I recall

What is the pattern Like 3-4-2 3-4-2 3-4-2 as an example

NOTE this translates to what the on-board computer THINKS the problem is but the computer is not all that smart.

Some things that can cause it
Low oil OR lOW OIL PRESSURE.. The sensors are offline during start

NO AC OUT Likewise. Sensor offline during start (That last can be major)

Several other issues.
bmwbob
Explorer
Mar 04, 2023
Ours will do that also IF either the oil level is low or the gas tank is not nearly full.
Since becoming aware of those issues and keeping things topped off, I’ve had no problems.
Bob
MNtundraRet
Navigator
Mar 04, 2023
Did you prime the generator before trying to start it.
It sometimes takes a few times to get enough fuel to start the engine.

By the way, you should always run the generator about an hour to dry out all components. There is a saying for generators: "Use it or lose it.".
Bobbo
Explorer II
Mar 05, 2023
When I had an ONAN in my previous MH, the ONAN manual said to exercise it for 2 hours once a month under 50% load.
wra
Explorer
Mar 05, 2023
I had a similar problem. The problem was the fuel shut off solenoid on the carb. It got stuck in the shut off position. Clean or replace it and it should be good again.

Having a low RV fuel tank could be a problem too. The gen gets its gas from the RV tank. The pipe that the gen gets the fuel does not go to the bottom of the RV tank. This keeps the RV from running out of gas by the generator use. There should be enough gas left to get to a gas station.
midnightsadie
Explorer II
Mar 05, 2023
I,ve hears this problem before go put fuel in the rv and see if it goes away gauges are not to be trusted.
wa8yxm
Explorer III
Mar 05, 2023
https://thecampingadvisor.com/onan-generator-fault-codes/
Lyman713
Explorer
Mar 05, 2023
Thanks for the replies. I'm saying it's not low fuel or other issues. It runs great, so long as I'm pressing the start button. (which bypasses the control board from shutting down the unit). So, I'm saying not fuel, carb, etc., as the engine side seems to run great (starts right away and I do try priming when I haven't run it that day).
Grit_dog
Navigator
Mar 05, 2023
Maybe not the issue but worth mentioning, the ecu or control board on the one Onan I had was NOT waterproof.
Basically brand new generator I washed the dust n dirt out of it and shorted out the board. Temporarily thank goodness.
If it got wet it could be the issue.