Just Back from Road Trip with a gen set problem?

[Dave Siegel]

We have an Onan 10K genset with a 4 cylinder Kuboto engine. It has worked fine for several years. I have finally cured my overheating problems and vapor locks but not a new problem popped up. Any one care to venture a guess?

We were coming home from Daytona Beach and had been on the road about 4 1/2 hours with the gen set running. (It works better actually when we are on the road.) All of a sudden I knew the roof top A/C was off but the gen set was still running. The temp was fine, and it's alternator was putting out fine. But the 120 gauges showed no electricity coming out. I shut off the gen set. It was cool enough to run with the window open and we made it home in an hour or so. I got in the driveway, and started the gen set. It started right up and was putting out electricity, according to my 120 gauges. The roof top A/C was not working. It ran for a few minutes and the gen set started to stumble, like it was running out of fuel. I shut it down. To check it out later.

I think I have enough fuel. (I filled it before we left and only used about 1/4 of the normal fuel. ) I will stick the tank to be sure.

I have not replaced the fuel filter in quite a while.

The above two things might explain the stumbling of the motor but why the loss and then remaining of the 120?

Any clues where to start looking will be greatly appreciated.

Thanks in advance.

Dave Siegel

[John Z]

Hey Dave, i sure do not have any help with the output section of your genset unless the 120 output just falls off when the Onan is not running at the correct speed, but by all means replace the fuel filter and see what happens then. The filter could be plugged enough to allow it to run at idle or low speed, but not allow enough fuel to let it run wide open. Sounds like a good trip though, -1 this morning and we are just dreaming about riding around with the windows open!!!

[TomC]

I can't help with that four letter word I hate to say (Onan) but, you might try to tighten all your circuit breaker connections, with the vibration of the vehicle, they loosen and then create more resistance.  I had this happen on my main double 50 amp breakers.  I just replaced them (cheap) but found they were loose. Other than that, you might have to take it to Onan-make sure you have that extra mortgage ready to go for the repair bill (this is why I dislike Onan-they make their own electronics and then charge big time for them).  Good Luck, TomC

[Nick Badame Refrig/ACC]

Hi Dave,

Check what Tom and John have told you, but it's also possible that you have a problem with your A/C. The fan may run but,

do you know if the compressor was running? A comp. trying to start up will sometimes trip gen breakers.

Another thing, If you have to go to Onan/Cummins, don't go to Cummins/Onan South in Ft. Myers.  I stopped in there last year

and I was treated poorly on top of the fact that they diddn't care to work on the RV units....I waited for over an hour there

before they told me that they couldn't help me.

Good Luck
Nick-

[TomCat]

I got VERY lucky when searching for an authorized Onan shop in the Colorado Springs area. I stumbled upon a hole in the wall shop near downtown, dirty as hell, with crap piled up to the ceiling all around the 'office' area.
Mack, the proprietor of Industrial Repair, is a magician when it comes to gen sets. They love him, and want nothing else but to make Mack happy.
Very fair on labor or parts prices, and doesn't mind educating you about your machine while he works on it. Has a sense of humor too...calls my converted Thomas "The Bookmobile"...LOL

If you find yourself on I25 through The Springs, and need Onan service, you'll be in good hands there.

Jay
87 SaftLiner

[Dallas]

I got VERY lucky when searching for an authorized Onan shop in the Colorado Springs area. I stumbled upon a hole in the wall shop near downtown, dirty as hell, with crap piled up to the ceiling all around the 'office' area.
Mack, the proprietor of Industrial Repair, is a magician when it comes to gen sets. They love him, and want nothing else but to make Mack happy.
Very fair on labor or parts prices, and doesn't mind educating you about your machine while he works on it. Has a sense of humor too...calls my converted Thomas "The Bookmobile"...LOL

If you find yourself on I25 through The Springs, and need Onan service, you'll be in good hands there.

Jay
87 SaftLiner

Geez, Tom,

That's a great description of our shop.... I haven't seen the office in about 2 months, but I think it's still there somewhere!

Dallas

[Ncbob]

Dave, having fooled with Onan generators for way too many years my first reaction would be to recommend that you change the fuel filter. The fact that on restart you had voltage leads me to think that you don't have a voltage regulation problem..unless it's intermittant...which is not typical unless it might be a corroded pin type plug. Just think of all the fun you're going to have solving this one.  Don't think it's time to panic and call the Dealer yet, though.

Many times aggravations like this happen with generators and from my experience it's all too typical that it boiled down to a forgotten or postponed maintenance item or simply the fact that the generator wasn't run often enough. In my opinion, both in boats and RV's the genset is usually the most forgotten party of the equation because, "it's always run before!"

Generators are susceptible to collecting dampness both in the engine and the generator end.  Periodic operation, under load (Like a couple of A/C's) does worlds of good in heating up the generator end and getting rid of accumulated dampness...and it doesn't cost a whole lot to do it monthly.

The next most important item is governor and speed adjustments. All generators, whether voltage regulated or not, need to be set by frequency (61 Hz..no load)...the voltage will generally fall in once that's set. WE forget how many appliances we use that are frequency sensitive. Clocks, computers,
DVD players and electronics...we can seriously cause damage by adjusting a generator with a voltmeter.

Didn't mean to be this long winded but we need to be reminded of these things periodically. If I can be of any further help...let me know.

Bob