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Bobchambe · 07-26-2021, 08:09 AM

I have an Onan generator in a 2016 Thor Hurricane 35C with only 261 hours.

The generator will start and run until I turn on the A/C, and then it sputters and immediately shuts down. It will restart with the A/C turned off.

Changed the fuel filter, no help.

TIA for any advice.

BigSkyBob · 07-26-2021, 08:19 AM

Has it thrown a code for the shut down? Possible air filter restriction?

twinboat · 07-26-2021, 08:29 AM

Dirty main jet in carburator.

Get some sea foam and follow the directions on the can.

Teamfoxy · 07-26-2021, 08:34 AM

I'm thinking the AC capacitor is going bad and it draws too much current. That should trip the breaker on the generator though and not shut it down. Do other appliances like the microwave & convection oven shut it down?
How is the oil level? Midway between the marks seems to work best.

rffowler55 · 07-26-2021, 09:02 AM

Not knowing what code is being generated it could also be a fuel flow issue, dirty fuel filter or bad fuel pump (unable to maintain adequate flow under load).

THenne1713 · 07-26-2021, 10:21 PM

Fuel pump failing is a possibility

Bobchambe · 07-27-2021, 04:51 AM

Thank you for all your comments. I ordered a fuel pump and will try that.

I know it's not a dirty air filter, too little or too much oil, and I don't think it's an AC capacitor at 261 hours.

THenne1713 · 07-29-2021, 11:22 AM

Yeah, short story= fuel pump fixed mine, 220 hrs, 17yo, LOL ��

Massparanoia · 07-29-2021, 11:40 AM

https://www.dropbox.com/sh/z713aum8w...mJkUrwq_a?dl=0

These may help

DadJokeDad · 07-29-2021, 11:50 AM

Do you have an altitude adjustment on yours? I was having a problem where it wouldn't start, or it would start and then die as soon as the AC kicked on. Gave me a code 37. I was at 6000 feet altitude, but the altitude adjustment was set to 0. I played with that and found that at 2000 feet adjustment, the generator would stay running, but rough.
Seafoam made it purr like a kitten.

SmilingSam · 07-30-2021, 11:28 PM

what capacitor ?

a start cap is not even used once gen started, and no cap would ever cause engine to stop running, unless on the control board!

there could be a ac cap in ckt, have no reason to think it would, but caps PASS ac voltage and BLOCK dc voltage so unless somehow it is being shorted to ground then NOT that, and yes if shorted to ground the ckt breaker will trip but should happen pretty quickly after any load.

remember if the onan 5500 then it has 2 ckts, and generally the second a/c is on the 2nd leg & little else although it can be wired any way the manufacturer desired.

It is likely just the load is too much for some reason, OR maybe the control board is simply not getting the feedback from gen and causing it to think or sense issues, control board senses voltage from the gen to determine how to best control gen, speed etc.

OR there could be an intermittent Oil pressure connection, it will shut gen off very quickly, a short ckt if pressure ok open if not probably ?

GL OP.

Quote:

Originally Posted by Teamfoxy

I'm thinking the AC capacitor is going bad and it draws too much current. That should trip the breaker on the generator though and not shut it down. Do other appliances like the microwave & convection oven shut it down?
How is the oil level? Midway between the marks seems to work best.

Bobchambe · 07-31-2021, 04:49 AM

The code is 36.

Shutdown without input from the controller!

Really? I know I didn't shut it off with the controller!

THenne1713 · 07-31-2021, 10:32 PM

re: Code 36, STOP button pressed, or LOW Oil would NOT give a 36, LOW FUEL (Less than 1/4-tank in Main?) would be a 36; Fuel Pump FAIL/ Intermittent would be 36