Community Forums

Mcgee43 · 07-23-2016, 09:47 PM

I have an Onan 7000 that was not producing any power out. Replaced the Voltage regulator and now get 120 volts to the coach. Problem is it will only run 2-3 minutes before shutting down. From what I have read, should I be looking at replacing the fuel pump?

We are new to this area of travel being recently retired after 29 years of fire service. We bought this gently used wheelchair accessible coach to see if we like traveling this way with our 35 year old daughter who has CP.
Thanks for any replies.

gruelens · 07-23-2016, 11:10 PM

I had the same issues, would run a few minutes and then shut down. It probably is happening when ambient temps are warmer. The fuel pumps are known for getting tight when warm outside (after they get some years on them). I replaced my fuel pump on my Onan 7000 gasser and problem was resolved.

Tha_Rooster · 07-24-2016, 05:53 AM

Is it throwing a code?

Mcgee43 · 07-24-2016, 08:31 AM

This genset does not have any lights on the control board that would indicate a code.
Model 7NHMFA26105H
S/N C000 069553

**CLIFFTALL** · 07-24-2016, 08:35 AM

The codes are ascertained by the blinking light on the start/stop /prime button.

Mcgee43 · 07-24-2016, 11:17 AM

This unit has no light what so ever on the control box cover . Only the start /stop switch and the 10 amp fuse slot.

cj23andout · 07-24-2016, 01:48 PM

If it throws a code, the stop/prime light should be blinking. You count the blinks to get the code.

There is a chart with all the codes in the owners manual. 983-0101.pdf

OK, I just uploaded the manual I use. Hope it works?

Mcgee43 · 07-26-2016, 08:32 PM

Gruelens;
Finally got the fuel pump replaced. The genset will now run past the 2-3 minute mark and still producing 120 volts. Now when I call for power
(Turn on the AC) it will run for 20-30 seconds then shut down. What I don't hear is the genset pickup in rpm to compensate for the power drop.
Now I wonder if I should look at the control board?
Thanks for your input and comments.

gruelens · 07-26-2016, 11:04 PM

McGee, sorry I am not a mechanic. Possible old gasoline could have the enrichment passage restricted in the carb. The carbs are notorious for this and today's fuel contributes to the problem. Carb is difficult to clean thoroughly and costly to replace. When you get the Onan running correctly, I recommend gas stabilizer for any gas that is going to sit more than two months.

TomandGloria · 07-27-2016, 01:55 AM

Sounds like the same issue I had with my 5500. Ended up being a bad fuel pump and the needle valve in the carb needed cleaning. The mechanic told me the same thing about fuel stabilizer in the tank. I normally run mine every 30 days under a full load, but going the fuel stabilizer route anyway. Pretty expensive fix.

Mcgee43 · 08-03-2016, 04:09 PM

The new fuel pump fixed the problem with the shut down issue. Now idles on low fine but when I call for power (AC running) the genset would start to surge (hunting, I think they call it) so bad it would shut down.
It was putting out the correct power (115-123)volts, I set the idle up just a bit to keep it from shutting down due to low power when surging. This actually smoothed out part of the surge. And it would run 1 AC unit but not both. After over compensating, I blew a curcuit or fuse somewhere when shu\ING off 1 of the AC units.
After I find the blown fuse, I think I should put on a new governor to correct the surging. And to clear the air, it uses the same fuel tank as the coach and has surged since I bought it. (Maybe a dirty main jet)
2000 Four Winds Infinity 35'

Big Oil Guy · 08-07-2016, 03:41 PM

I had a 7000 gas Onan that acted similar to the way you describe. Simple fix was to remove the plug on the bottom of the carb sediment bowl and drain the gas from it. When it refilled, it must have flushed out whatever the problem was and it ran fine! Hope yours is a simple.

Mcgee43 · 08-15-2016, 11:17 AM

Since the last post, I have ran some gas with seafood out of a separate tank through the carb a few times and let it set for 12 hours or so before repeating the process. And changed plugs again, this really smoothed out the genset.
While looking for the blown fuse, I made it to the transfer switch. With the genset running I can get 120 volts to the box but not out of it. Further investigation revealed a burnt area under the small circuit board. I think this is the culprit.
Does anyone know if I can buy just this board?
This is for a PS245L power switch from Todd Engineering Sales.

Mcgee43 · 09-18-2016, 05:43 PM

Ok, it's been awhile since I have posted any progress. Due to a couple of planned trips we have just endured the heat in the coach while traveling to the destination.
I replaced the power transfer switch but still had issues with the genset shutting down when calling for power. After racking my brain and contacting a local independent RV guy, I finally faced my fears and pulled the carb to clean or replace ( $360) ok think I'll try the cleaning. Fairly easy job once I got into it. Just shut it down after running both ac's and full load for an hour. Job complete! Just in time for camping at Bikes, Blues and BBQ in Fayetteville. Thanks for all the advice, this is a great Avenue for finding solutions to problems from fellow RV'ERS not someone trying to get in your pocket.
I'll visit often, maybe I can contribute someday.
Rex McGee
MCFD retired