generator shutting down

I know that this has been asked before but nothing really fit my problem so I'm asking again...
  I can turn on my 4k onan generator on my Winnebago Vista 26 and then turn on my A/C...runs fine, in fact it ran for over an hour the other day. When I started the coach to drive down the road, the generator shut down before I could get 5 miles down the road It will start back up just fine and run...as long as I'm not driving with the A/C on, Any thoughts?
Thanks,  Brad

Charger1204 said:

I know that this has been asked before but nothing really fit my problem so I'm asking again...
  I can turn on my 4k onan generator on my Winnebago Vista 26 and then turn on my A/C...runs fine, in fact it ran for over an hour the other day. When I started the coach to drive down the road, the generator shut down before I could get 5 miles down the road It will start back up just fine and run...as long as I'm not driving with the A/C on, Any thoughts?
Thanks,  Brad

Click to expand...

Have you checked the oil level of the generator? It may be on the hairy edge of shutting down because of low oil level and when you start down the road, the oil moving around the sensor tells it to shut down.
I just read yourgain post and I'm getting the impression that the generator will run OK all the time as long as the Air is not on. Is that correct?

Rene T...That's correct, the generator will run while driving down the road as long as I don't turn the house A/C on. And the oil is the very first thing I checked. Very odd. I've checked the fuel line as much as I can see and it appears to be good. I would have to drop the tank to see all of it completely to the tank.

Oh, I was assuming this was dash air you were talking about but it's your roof air. How does the generator shut down - via a signal to the stop switch or is the breaker tripping?

The gen just bogs down, like it would if you tried to turn the A/C on right after you start the genny. I've tried to catch it shutting down so I could see if it gave a code while bogging down but I've not been able to catch it. I've put some seafoam in the tank to help get rid of any carbon or gunk build-up. When I purchased the MH it was 5 years old and only had 34 hours on the generator.

The 34 hours kind of gives it away. The carburetor probably needs cleaning or a rebuild/replacement. These carbs get clogged real easy while using today's gasolines and when not used regularly.

I think Stu is on-target with his evaluation.

I knew I could get some good advice from this sight...Lots of experience on here.

Thanks All

It is most likely the fuel pump and Filter.  Onan had a run of bad chinese pumps and are now using Airtek as an OEM.
Onan Generator running issues - What I learned. Onan (now owned by Cummings) Generators are famous for Fuel Pump failures. If you having trouble starting or under load the generator quitting, you might have a failing fuel pump. The price for a replacement is rather expensive at $75 to $100... but never fear there is a solution. The company Airtek OEMs the Fuel pump to ONAN where they stamp their name/part number on it and mark it up.
This is the Airtek Fuel Pump (picture #2) I needed for my Onan Marquis Gold 5,500W generator. At only $42 it was a bargain. Been running like a swiss watch for over two and half years.
DON'T Forget to change your Fuel Filter(s)!!!
Picture #1 - Onan (Cummings) part (made for Cummings by Airtek) Cummings charges $75-$100
Picture #2 - Airtek part ($42) (Wow! now $39!)
https://www.amazon.com/Airtex-E11015-Electric-Fuel-Generator/dp/B0076D5OI2/ref=sr_1_12?ie=UTF8&qid=1509726343&sr=8-12&keywords=airtex+fuel+pump

ALSO HIGHLY RECOMMEND DUMPING ABOUT 4 OR 5 CANS OF SEAFOAM Gas Treatment in your (full) RV tank.
One pint treats 8 to 25 gal in all types of gas. (Use 1 oz. per gal.) Add more to clean, less to maintain.
They claim you can safely mix Seafoam to gas as a 50% solution for serious cleaning. I would not go that strong. 
It will clean your Engine and Generator over time.
I noticed a big improvement in gas mileage and performance on my 8.1 GMC.