High temp. shutdown on onan generator

[Phil H / Chicago]

Until now the onan 10kw generator has been fine. The unit is in a 1999 american heritage and has about 3900 hours on it. Would run for hours with no problems, but recently it has started acting up and now has gotten consistant with the same problem. Now I try to run it and it will run for about 10 minutes and then it will shut down and show the high temp. light flashing. The fluid level is fine and I can't see any other problems. When I look at the computer screen inside the rv and scroll through the readings and come to the generator temperature it reads 104 at all times, even if the generator is running or not. I looked back through some of the paperwork that the previous owner gave me and noticed he had had the same problem about 18 months ago and took it in to be serviced and they concluded that it needed a new radiator so they replaced it. I called him and talked to him about it and they said at the time they could not figure out what the problem was so they just put the radiator in as a option to fix it. Not even sure if it needed it. Any suggestions on what to check?

Thanks, Phil

[TomC]

Sounds like a faulty high temp shut down.  If it is getting a false signal, even 104 degrees maybe high enough to shut it down.  I would replace the sensor on the engine, clean up the connectors, and possibly also change the thermostat.  Unfortunately, Onan's are both complicated and expensive to repair.  That's why I chose a Powertech with mechanical controls-no electronics.  Good Luck, TomC

[Hartley]

If it's an Onan, Check the fanbelt and tension on it.
The Onan belt is a special type.

It also depends on whether you have a Kubota or Isuzu engine. They
both use metric belts and you have to know what engine you have.

Mine went through 3 generic belts in 1 week. I got the right belt and it has lasted for over a year.

Dave....

[Nick Badame Refrig/ACC]

Hi Phil,

I had the same problem twice...  It's what Dr. Dave just told you, the belt wore out and is very loose.

I have the Onan 12.5 QD and your 10kw is the same enclosure. The top lid, the right side cover, the fan shroud, and pully all

have to be removed to replace the belt. I keep 2 extra's on board and they cost about $50+ each. You can't even use a generic

belt because the onan belt is metric. A generic belt that I used in the past only lasted 1 month.

Good Luck
Nick-