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roller183's avatar
roller183
Explorer
Jan 29, 2018

5500 Onan quits after 1-2 hrs use, then starts back up

Was out dry camping this weekend with the ATV club and had a new issue with the generator pop up...

gen was running smooth and steady for at least 1 1/2 hours then quits like I turned it off...No fuel stumble, just like it was turned off..Would not restart right away..Wait for 2-3 minutes, start back up and will run for another 1-2 hours and stop...

The best code I could pull from it was a "34" ..Can't find a fault code list to save my life. Looked at Cummins page, nothing. Did searches no luck..

I'm hoping it is something simple like the last time where a rodent had chewed the wires....

Anyone have similar issues?

TIA. Checked the search engine here but probably used the wrong wording.
  • Onan 5500 Marquis? They don't have inverters as far as I know. Check oil level and suspect fuel pump. With genny not running, press stop switch (prime) and listen for the fuel pump to run. When genny quits, immediately try that again and listen for fuel pump. Fairly common failure mode for fuel pump. They overheat and stop running, cool down then start running again. With sufficient load, sounds just like you shut it off, no surging.
  • A very quick Onan search came up with 34: high inverter temp

    Debug from the op manual

    Make sure nothing is blocking cooling air inlet or outlet
    Reduce the number of appliances (could be altitude related)