Onan Generator

Have you exercised it at all in the four years you have owned it?
Are you plugged in to shore power?
This all helps in diagnosis

most cummins shops work on them.

Are you sure it is not a Diesel Gen and not a Gas Gen? What model MH? Is your MH gas or diesel?

It has been run 35 hours in the past four years. My initial guess is that there is an electrical failure in the generator side and the engine is not getting a signal to keep running. Other possibilities are low oil level and sensor is shutting down for that or fuel starvation from partially gummed up fuel line won;t provide sufficient fuel to support the load when the generator once it tries to pick up the load.

I wonder if there are any codes? There is a light on the switch, it should provide an initial code such as 2 blinks followed by 1 which leads to another code which can be found in the manual. This is where real trouble shooting begins after checking out the simple stuff like oil level.

Sorry. The motorhome and generator are diesel. We used it earlier this summer, and it worked great. I am plugged in to shore power, but just enough to keep the batteries up. I was checking it again today and noticed that the fuse panel in the rear of the motorhome was clicking after the generator quit. Significance?

landman02 wrote:
Sorry. The motorhome and generator are diesel. We used it earlier this summer, and it worked great. I am plugged in to shore power, but just enough to keep the batteries up. I was checking it again today and noticed that the fuse panel in the rear of the motorhome was clicking after the generator quit. Significance?

Some generator hookups are designed to shut off after a few minutes if they sense shore power to the rig My MH is set up that way. If no call for power from the Motorhome because I am hooked up to shore power.the genny shuts off.
Try unplugging and see if it works.
Additionally the manufacturer suggest running the genny under load for an hour or more a month. This minimizes corrosion on the parts that produce the electric. If they get corroded enough you will get no power

I unhooked the shore power and tried it, but still no luck. I have contacted a Cummins shop in OKC, but can't get in till Tuesday next week, and it is about 100 miles south of me. I guess I should be glad diesel is less expensive right now. I will keep trying additional suggestions till then. Thanks for everyones help.

Is the generator level? Unlevel may cause low readings to the fuel level and/or oil level sensors, forcing shutdown.

Here are some of the possibilities from the troubleshooting section for Onan BGM and NHM sets. Not knowing if yours is either one, I'd still think it's all pretty generic in the control section, maybe it will give you somewhere to start. This may be stuff you already checked.

Trouble: Engine starts and run, then stops. Set re-starts immediately, or after cooling down.

Possible Causes:
1. Fuel level or oil level is low.
2. Dirty fuel filter restricting fuel flow.
3. Faulty ignition module
4. Contaminated fuel

Corrective Action:
1. Check fuel and oil levels, refill if necessary
2. Clean or replace fuel filter.
3. Replace ignition module
4. Refill tank with fresh fuel.

Good luck with it!

What are the fault codes. Indicator is on the start switch. To get level one fault code just read the blinking light. To get secondary fault codes push switch bacl (opposite of start) and read the codes. I am willing to bet it is a fault code 33 and it is reading an overheat. Its probably no overheating but the temp sensor is probably reporting that it is. A known problem with that generator. If it is it will run for EXACTLY one minute...no more, no less.

How much fuel in your tank? My generator draws fuel from the same tank as the engine. Fuel pick-up for my generator won't allow the generator to run if there is less than 1/4 tank of fuel.