I have a 2003 Bounder D/P with Onan generator. On 50amp shore power I can get both AC's to run but on the generator I only have the rear unit. The thermostat shows that I have them both turned on "Cool high", and I set the temp to freezing and still only get the rear one to come on, the front doesn't come on even if the rear is off. If I turn on shore again, I get both. My generator spools up a little when I engage the AC unit. My inverter is off, really don't know what that thing is for. lol...Both of my furnaces run with shore and generator power. I checked the breakers, none are tripped, and I checked the fuses under the dash, under the bed, and on the wall by the inverter/charger. Anyone have any ideas what is wrong?

Oh, and my electrical outlets do not work on generator either but they do on shore power. I cannot get power to the microwave no matter what I try, as well as the block heater. Just some additional info in case it helps.

I'd say the front circuit for your generator is either not turned on or the circuit breaker is no longer functioning. That is the CB on the generator itself, not a CB in your load-center further downstream. I'd recommend checking generator output with a meter, before and after the CB's on the generator panel.

Your Bounder probably has the 5500 Onan and it cannot run both AC's.You have 12,000 watts available with 50 amp and ony 5500 with the Onan. It can only run 1 AC, especially older ones.

Sorry, it's a 7500 Onan, and I have run both AC s in the past, which is why I'm baffled now. There is one main breaker on the Onan, it's on. Not sure where the others may be.

The 7500 has 2 120V circuits so it sounds like one of them is not working which could be the gen, gen CB, your ATS so some wiring in between. Somewhere the 2 neutrals will be bonded, perhaps in the gen. Start with the ATS and see if you have AC voltage on both input legs and then both output legs. Since it works on shore power one of the output legs will have no voltage. If both input legs are good then you have an ATS problem.

Power to AC's on Generator | Good Sam Community

56 Replies

brobox
Explorer
Nov 13, 2012
Check the contacts on your transfer switch. That is where your shore power cable is connected to the MH. It sounds like one leg from the generator is not switching.
CA_Traveler
Explorer III
Nov 13, 2012
The 7500 has 2 120V circuits so it sounds like one of them is not working which could be the gen, gen CB, your ATS so some wiring in between. Somewhere the 2 neutrals will be bonded, perhaps in the gen.

Start with the ATS and see if you have AC voltage on both input legs and then both output legs. Since it works on shore power one of the output legs will have no voltage. If both input legs are good then you have an ATS problem.
Branman1971
Explorer
Nov 13, 2012
Sorry, it's a 7500 Onan, and I have run both AC s in the past, which is why I'm baffled now. There is one main breaker on the Onan, it's on. Not sure where the others may be.
Jim_Cindy
Explorer
Nov 13, 2012
Your Bounder probably has the 5500 Onan and it cannot run both AC's.
You have 12,000 watts available with 50 amp and ony 5500 with the Onan. It can only run 1 AC, especially older ones.
Steelsmith
Explorer
Nov 13, 2012
I'd say the front circuit for your generator is either not turned on or the circuit breaker is no longer functioning. That is the CB on the generator itself, not a CB in your load-center further downstream. I'd recommend checking generator output with a meter, before and after the CB's on the generator panel.
Branman1971
Explorer
Nov 13, 2012
Oh, and my electrical outlets do not work on generator either but they do on shore power. I cannot get power to the microwave no matter what I try, as well as the block heater. Just some additional info in case it helps.

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Power to AC's on Generator

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