Onan Gen Set problems OR coach wiring issues

2002 Damon Intruder 350 class A
Onan 5500 generator

Our gen set will ONLY run off 1 of the 2 breakers, powering only half the coach, rear end mostly. Front Air, micro, front ac outlets, tv, not working.

Try to turn on both breakers, gen set would shut off after 2 or so seconds, flash code 27. Would not charge coach batteries either.

Plug unit into shore power, ALL works fine. (except gen of course)

Anyways, Dealer where we bought it was no help.  Took it to Cummins yesterday.  They called a short time ago, was told they pulled the gen set out of the RV, hooked it up, it ran PERFECT.. both breakers on, full load, all was great with it. Only charged us $130.13 out the door for labor and test.  This was a large, dedicated Cummins / Onan dealer/parts/service center located in Columbus Ohio.  Bridgeway Cummins.

Was also told that it has to be wiring issue somewhere in the RV, from the gen set to where ever, that is causing a short back to the breaker cutting it off. They don't do that sort of work, so this is on me pretty much as I am not going back to the dealer.

Now. "could", the inverter cause this? I've already replaced the converter with a new one. I have had issues with the rig plugged in and having to reset the small breaker on the inverter.

Or am I looking at a cut wire, outlet bad, or what?

I'm HAPPY as hell our gen set is good! Dealer wanted $600.+ to do what Cummins did. The dealer also told me I had a bad choke pull off, Cummins said nothing is wrong with the choke.

Thank you.

If you suspect the inverter , disconnect it and test genset but probably a wire somewhere , perhaps a mouse got hungry and caused a short . Process of tracking down / eliminating one thing at a time I'm afraid. Might be able to speed up the diagnosing by using the  "halves"  principle,  wire starts at A  goes to Z ,  disconnect  at  M  , if Ok now (genset runs OK ) you know it is somewhere between L  and Z (as L was OK, need to restart there) . If still a problem when disconnected at M  , then disconnect around G  and try to run genset
Hope that makes sense and good luck

nfredrick said:

If you suspect the inverter , disconnect it and test genset but probably a wire somewhere , perhaps a mouse got hungry and caused a short . Process of tracking down / eliminating one thing at a time I'm afraid. Might be able to speed up the diagnosing by using the  "halves"  principle,  wire starts at A  goes to Z ,  disconnect  at  M  , if Ok now (genset runs OK ) you know it is somewhere between L  and Z (as L was OK, need to restart there) . If still a problem when disconnected at M  , then disconnect around G  and try to run genset
Hope that makes sense and good luck

Click to expand...

NO that don't make sense.

If you keep trying to run the generator with a short you WILL hurt the generator. If you know nothing about electrical, you might be better off getting an electrician to look at it. If everything works on shore power, then it is either in the transfer switch or the wiring from the generator to the transfer switch.