Onan 4K generator shuts off

[apr67]

Originally Posted by mstng

Hello guys, an update.
Back at it with the generator. Very hot day with temps close to 100 and unbearable humidity. Almost convinced that over heating must play a part as suggested in generator shutting off. Pulled some oil off down from the full mark to the add mark and its been running for over 2 hours with AC cycling on and off, no surges and no stopping. Whether this is coincidence or truly helped I have no idea. It was recommended elsewhere and some of you may have some insight to that. Time will tell if truly fixed.
Why it would start from the generator start switch but not from the cab switches I don't know. Low voltage perhaps? Cables are secured. It's fine now but has been plugged in for a week.

Thanks for your thoughts.

The generator will tell you why it stopped most of the time, if it was heat it would have an error code.

https://www.youtube.com/watch?v=q3gJvJaBtO8

[mstng]

Finally found the culprit. Hope this helps someone. Tried to start the generator today using both inside switches as well as the generator switch. No spark. Removed battery and played around with the breaker as suggested with no change. Going down the list of things to check I remembered quote from Javelin..

"Do you mean no cranking at all; or cranked OK, but no start? Since both remote switches fail to do their job.....look for a common fault where the remote y cable connects to the local switch at the generator......might be a loose connection; loose pin in a connector; bad termination; broken wire etc."

I had to jiggle the air filter to get it in a couple days ago and thought I may have loosened something. I found the cable coming into the generator was loose and not secured. It came from the factory this way as the nut was fixed and wouldn't tighten. The cable wasn't pushed through the opening enough to fit flush on the bolt. It was sort of wedged onto the bolt but not tightened down. Apparently when the generator cycles up or down we all notice vibrations and this I think was why I was having intermittent problems. Sometimes the inside remote switches worked and sometimes only the cable at the generator. I added 3 washers to get the nut to grab and tighten as it wouldn't thread all the way I think from the sprocket washer and burn marks on the nut. A bit of an idiot that I didn't check this first especially with something from the Thor factory.

[The Gritz Carlton]

This guy will say the same thing 10 times per minute, it hurts to listen to him but this seems to be a real solution to a real problem. Yesterday I had my MH at the Cummins Shop for generator service...I asked the tech about this...he said "YES...it is a real issue and YES...a slightly high oil level will shut it down". FYI: They charge me $225 for oil and filter change, fuel filter change and 50 point inspection which includes any updates and adjustments. May be a bit high but pushing buttons is all I care to do.

https://www.youtube.com/watch?v=vzXDlln8aUw

[apr67]

Originally Posted by The Gritz Carlton

This guy will say the same thing 10 times per minute, it hurts to listen to him but this seems to be a real solution to a real problem.

The 4k Onan's are splash lubed (even the ones with oil filters). It makes perfect sense that being over full causes a problem and leads to shutdown. It seems like Onan messed up on the dipstick and either designed it to be checked like the 2800's (unscrewed), or just screwed the pooch.

[Tom N3EQF]

Originally Posted by apr67

The 4k Onan's are splash lubed (even the ones with oil filters). It makes perfect sense that being over full causes a problem and leads to shutdown. It seems like Onan messed up on the dipstick and either designed it to be checked like the 2800's (unscrewed), or just screwed the pooch.

By the way, later versions no longer use the oil level detection as a shutdown trigger. Mine is a spec "P" from 2014 manufacture and does NOT include any oil level sensor. (4KYFA26100P part number - the "P" at the end of the number is the specification designator).