generator only runs when i hold the start button on

[JDKing]

on a propane onan 6.3kw genny in a 1994 safari sahara 34'. it will start and run for about 2-3 seconds then die, but if i hold the starter on is will keep running. i just changed the oil and its full, changed the plugs gapped to .024'', changed the air filter, should be good to go right... its not and we are trying to get out of town tomorrow!!! we ran the unit about a month ago and 3 hrs into our trip it would load up and stop making electricity, but it would keep running very rough. it would cycle elect on, then of, then on, then off from 3-5 munites each time. luckily we had a back up on the trailer so we connected it and just ran with it, honda good, onan bad!

need some HELP!!!!

[Bob86ZZ4]

It sounds very similar to a problem I had on an Onan 4k gas in my old mh. I took it to a good generator guy and he tracked it down to a bad rotor. He said it wasn't generating a/c. It would start and die because there is something that kills it if it isn't making a/c I guess. At least that's the way I understood him. I could keep it running by holding on the start button. But it still wouldn't make a/c. He put a new rotor in and it worked great until I sold it a few years later. The rotor is a very expensive part. I hope it's not your problem. It's not the rotor in the distributor. It's a big round thing that spins to generate the a/c voltage. Good luck.

[Bill Adams]

You might want to check the fuel regulator. I had a similar problem with a similar propane generator (the worst possible fuel source from my previous experience) and if you hit the regulator with the end of a broom stick (the only thing I could find that would reach) it would run until the next time you started it. The dealer replaced the regulator and it run just fine after that.

[stubeje]

My uncles DS did the same thing...there is a small control board on the Gen. that draws moisture and corrosion will form on the traces (back of board) which shorts out the "run" funtion. As long as you hold the "start" button it would run. I just un plugged the board, cleaned the corrosion off the back with alcohol and a tooth brush and re-installed...walla...generator starts and runs fine now. His was an LP Onan also.

[JDKing]

Quote:

Originally Posted by stubeje My uncles DS did the same thing...there is a small control board on the Gen. that draws moisture and corrosion will form on the traces (back of board) which shorts out the "run" funtion. As long as you hold the "start" button it would run. I just un plugged the board, cleaned the corrosion off the back with alcohol and a tooth brush and re-installed...walla...generator starts and runs fine now. His was an LP Onan also.

pulled it off this morning and its filled with a clear rubber, no way to clean it.

dont know how to check the rotor, and the regulator is working.

[Gary RVRoamer]

The start switch bypasses a couple safety cutoffs, particularly the "no oil pressure' and "no AC output" cutoffs, so check those if you can. It also primes the fuel pump, so it could be the normal power to the genset fuel pump isn't working.

[JDKing]

Quote:

Originally Posted by RV Roamer [Gary] The start switch bypasses a couple safety cutoffs, particularly the "no oil pressure' and "no AC output" cutoffs, so check those if you can. It also primes the fuel pump, so it could be the normal power to the genset fuel pump isn't working.

i looked for the low oil pressure switch bu couldnt find anything on the motor, everything is very tight in there.

[Rodney T]

Had the same problem several weeks ago cleaned the comutator rings with scotch brite on a thin stick (Removed the brush holder) and diconnected spark plugs :-) used starter to rotate

[R&K Mobley]

Another thing to look for, will it run if you hold the throttle open a little by hand? If so I had a Onan 7000 on my 04 Bounder that shutdown and would restart and run for a min or less and shut down again. The linkage to the governor has a plastic clip that was flaky and the linkage came out. If yours is anything like a gas 7000 this is accessiable from a square access hole in the top of the enclosure.

[JDKing]

will not run by holding the throttle open... tried that. i will try and see if i can get the brushes out and clean the commutator ring a majig... but i did drive it 2 hrs to and from yogi with no a/c!!! windows open, it was HOT!!!!! the things we will do for our family...

[Rodney T]

Just an added note I didn't see mentioned
There is a oil pressure switch that shuts it down if no oil pressure a clip lead across it is a quick check

On my gen it is next to the oil filter, I had to remove a cover that only allowed the filter to fit to get to it

I have had Mr murphy aboard after I got the gen running &*@&^%!# (I am now waiting for the delivery of a new Transfer Switch :-)

[RJay]

A faulty voltage regulator will cause the problem your have. If it's not the regulator it's the control board.

[wa8yxm]

A few years ago in Quartsite AZ some friends of mine, who were parked next to me, had just that happen.. The blink code was "Low batteries or not cranking fast enough"

Turns out the brushes had worn out on the generator and since the Onan was NOT detecting 120vac out.. It simply shut down (I mean why waste gas if you are not generating power)


Thankfully for them they were parked next to a couple of part time 30 amp outlets (MY RIG) so they had power whenever MY generator was running.

But.. Still.... That is one very expensive (I might add) option.

I will point out it is one on a long list.. Since I don't know the rest of the list, which includes among other things the oil level sensor... I won't even try to list it.

[hamdave]

Quote:

Originally Posted by RJay A faulty voltage regulator will cause the problem your have. If it's not the regulator it's the control board.

I vote for this response, was the problem that I had. bad VR (diode) set blown on the regulator. I replaced the diode set and all was good again.

cheers