Onan 6000 quiet diesel with 1,600 hours. Used to be able to run both 13.5 A/C's with no problem. Now, with the front A/C running, and then start the back A/C unit, the genny dies. Flashes code 22 which is overload condition. No breakers blow. And the genny will restart right away.I measured the A/C load at start up at 18 amps and at 8 amps while running. Both A/C's pull the same load. Both a/c's run fine off a 50 amp plug in.I think the genny THINKS there is a overload condition, but I don't really think there is one. I think some sensor went bad. Had the genny checked out by Onan technician. It was given a clean bill of health.I'm not so sure.Any ideas???

Since the generator checked out there may be a issue with one of the AC's pulling more than it should. Have you tried starting the rear AC first? Maybe it's pulling more at start up than it use too. Also have you tried to push the generator in different ways? Try one AC plus the microwave and a hair dryer, enough to come close to full load.

Mine did that and it turned out to be the start capacitor on the roof air. Go to youtube and watch a few videos on testing and replacing both the start capacitor and the run capacitor.

x2 on the caps. Sounds like a faulty start cap.Some info. here. RV AC capacitors As mentioned, if you are going to take a cap. out, short it out first to discharge it. If you can't test a cap., I would just go and replace one first and see if that fixes it. If not, re-install it in the other AC. Or spend the extra $20 or so and just replace it in both AC units. I guess it's also possible to be a faulty start relay but more likely a cap.You won't be able to measure the actual startup current with a multi-meter. It actually goes as high as around 6 times the run current for a small fraction of a second and it won't show on your meter. You can find the starting current in a AC manufacturers tech. data.Some info. and pricing on Coleman caps.: Coleman AC parts Maybe you have another make though.

Also - I have read that as air conditioners age they draw more amps especially during startup - sometimes a hard start capacitor will solve this issue.

Or your fuel filter is clogged. Have you serviced it? QD is an inverter type genset. It steps up the RPM when the load increases and if the ff is clogged, it dies from lack of fuel. Shuts off as it can't regulate the load.

When the back A/C starts, the genny dies! | Good Sam Community

16 Replies

stillthinking99
Explorer
Mar 14, 2014
Ksg5000, sorry my post wasn't clear that I'm not the OP. I was sharing my experience
with time to go now. My fault.
ksg5000
Explorer
Mar 13, 2014
Congrats - glad the replacement caps solved the problem - the fact that their inexpensive is a bonus.
stillthinking99
Explorer
Mar 13, 2014
I went on the roof, took off the ac shrouds on both and d got part numbers. I also bought an $80 multimeter that would test capacitance. It has a setting called, "cap." Both ac's start caps were bulging and leaking tar...I took that to mean replace both. Both run caps tested good so I left them as is. After replacing start caps on both ac's they worked during testing and again during a trip.
time_to_go_now
Explorer
Mar 12, 2014
myredracer wrote:
x2 on the caps. Sounds like a faulty start cap.

Some info. here. RV AC capacitors As mentioned, if you are going to take a cap. out, short it out first to discharge it. If you can't test a cap., I would just go and replace one first and see if that fixes it. If not, re-install it in the other AC. Or spend the extra $20 or so and just replace it in both AC units. I guess it's also possible to be a faulty start relay but more likely a cap.

You won't be able to measure the actual startup current with a multi-meter. It actually goes as high as around 6 times the run current for a small fraction of a second and it won't show on your meter. You can find the starting current in a AC manufacturers tech. data.

Some info. and pricing on Coleman caps.: Coleman AC parts Maybe you have another make though.

So, Coleman does not list a part number for a start capacitor. They now list a "hard start" capacitor. Can anybody tell me the difference?

Seems cheap enough to order up a pair of these and just install them.
AH64ID
Explorer
Mar 12, 2014
Then it's looking like a failed capacitor.

The SUPCO SPP6E is a good replacement that packs a little more power than the OEM stuff.
time_to_go_now
Explorer
Mar 12, 2014
ah64id wrote:
time_to_go_now wrote:

I did just change my four golf cart batteries because the old batteries were bad. And crazy enough, it allowed the front A/C to start when it would also kill the genny on start up.

You could try turning the charger off and see if it helps.

I have. That does not make any difference.
time_to_go_now
Explorer
Mar 12, 2014
Big Katuna wrote:
Or your fuel filter is clogged. Have you serviced it? QD is an inverter type genset. It steps up the RPM when the load increases and if the ff is clogged, it dies from lack of fuel. Shuts off as it can't regulate the load.

I have replaced the fuel filter exactly for that reason.
AH64ID
Explorer
Mar 12, 2014
time_to_go_now wrote:

I did just change my four golf cart batteries because the old batteries were bad. And crazy enough, it allowed the front A/C to start when it would also kill the genny on start up.

You could try turning the charger off and see if it helps.
time_to_go_now
Explorer
Mar 12, 2014
JiminDenver wrote:
Since the generator checked out there may be a issue with one of the AC's pulling more than it should. Have you tried starting the rear AC first? Maybe it's pulling more at start up than it use too.
Also have you tried to push the generator in different ways? Try one AC plus the microwave and a hair dryer, enough to come close to full load.

Yes, I can put all kinds of other load on the genny without issue.
time_to_go_now
Explorer
Mar 12, 2014
ah64id wrote:
The caps are a good place to start, but have you done any battery bank changes lately?

When I went from a single G24 to a pair of 220AH batteries my 2K genny would no longer stark my 9K BTU a/c with the converter on whereas before it would them both without issue.

So if you have upgraded the charger and/or batteries it could be drawing more than you think. If not I would start with the caps.

I did just change my four golf cart batteries because the old batteries were bad. And crazy enough, it allowed the front A/C to start when it would also kill the genny on start up.

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When the back A/C starts, the genny dies!

16 Replies

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