Onan Generator Trouble - Won't Run With Load

Thanks, all good ideas. Lots of videos on youtube about sliprings, who knew? Our first stop on our trip is Reno (Hot August Nights) and we're told there is an Onan shop close to our campground if we don't get it going. I'll let you know

Skip the local RV service center and call someone who works on generators. Just because it's bolted to an RV doesn't mean an RV service center is the only one who can work on it. Bet thier labor rates will be less and they will do house calls.

oldcarfun wrote:
The fuel bowl is full when it quits so I'm assuming it's getting fuel. It surges when loaded like it's supposed to. Where are the slip rings to check? Thank you

On mine, (Onan 5500, gasoline) I have to remove the air cleaner assembly....simple enough, only a couple of screws,....and there is a plastic cover over where the brushes are. That cover on mine is the cover for the brushes. Remove that cover and you should be able to see the slip ring...it looks like white plastic with a brown/copper ring around it on the end of the rotor. You can probably see the slip ring good enough to shoot cleaner at it through the vent slots over the end of the rotor. Just spray some contact cleaner towards it while running. Be careful with the moving parts, though, so that you don't get the spray tube from the contact cleaner too close and caught in it and/or you don't get your fingers in the moving parts either!

Brushes and slip rings info

There is/was a video on line, but I don't know if it's still up.

The fuel bowl is full when it quits so I'm assuming it's getting fuel. It surges when loaded like it's supposed to. Where are the slip rings to check? Thank you

Sounds like it could be a fuel supply issue. Does it surge a little when you switch on a load? It should, and then recover. If not, then your governor may not be working adequately enough to compensate for the load and the engine shuts down from not getting enough fuel to keep running under load. It could also be the fuel pump...nothing says a new fuel pump can't go bad or a new fuel filter can't get stopped up. Gasoline these days is horrible.

I assume that the oil level is adequate? If not, then then the low oil pressure could be cutting it off.

Also, some gensets will shut down if they are not producing power. You may want to clean your brushes and the slip ring to make sure there's good contact between the two. You can use a can of contact cleaner or brake cleaner and while the genset is running, spray it on the slip ring. There should be enough friction between the brushes and the slip ring to clean off any built-up carbon or other contaminants. Of course, depending on usage, the brushes may be worn to a point that they are losing contact too.

Just a few more suggestions.

I,D look at the hoses, if there real old one could be colapsing, and it could be your AC going bad pulling more amps than the genset can handle.take a amp reading on the ac when runing.

sounds like a weak fuel pump

The fuel pump has been replaced since we've had the coach but that's not to say it might have failed again. It's getting fuel because it's running. I've just replaced the filter during this issue.

It is usually a fuel filter or fuel pump issue