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Generator won't stay on

Posted: Mon Jul 27, 2015 9:04 pm
by Saprophyte
I'm gaving some trouble with the Onan 2800 on my B190. I'm hoping somebody on here can help.

When I try to start, the generator turns over and actually runs while I hold down the starter. As soon as I let off, though, it shuts down again. The red light that means the generator is running stably never turns on any more. I start it with the van engine running, to get as much available starting current as I can, but no generator. I hold down the gen starter for up to 5 seconds at a time, for over ten times in a row, and the result is the same. The engine runs only as long as I hold down the starter.

Any suggestions?

Thanks.

Re: Generator won't stay on

Posted: Mon Jul 27, 2015 9:53 pm
by skater
That's exactly what mine was doing before I replaced it. Check the circuit breaker in the gen and all, but you'll probably have to pull it and start diagnosing it.

Re: Generator won't stay on

Posted: Tue Jul 28, 2015 10:43 am
by Reddeer
It may be something as simple as a new spark plug and a carburetor adjustment. If you are not mechanically inclined, you'll need to find someone that is. I use an small RV repair shop that is very reasonable.

Re: Generator won't stay on

Posted: Tue Jul 28, 2015 2:49 pm
by lido14co
There's a great troubleshooting guide at www.flightsystems.com that should help you find a solution. I checked several online forums and many people have said it's probably the regulator. Here's a quote from one of the forums:
"Post New Message To the ones who are experiencing their generator shutting down once they let go of the start switch. It is probably due to one of three things. The slip rings could need cleaning. Generators should be exercised (run) a minimum of a half hour per month to keep oxidation from forming on the slip rings. Typically many RV generators are not run at all for months. It could be a faulty circuit board, or it could be a faulty voltage regulator. flightsystems.com has a great trouble shooting guide that you can print out to isolate the problem (I just went through all this)They also sell after market boards and controls, but the trouble shooting guide is free. Hope that helps."

Also, it's very important to run your generator monthly. I think Onan recommends 2 hours a month (I run mine for an hour but I live in a fair weather climate).
Good luck and I hope this information helps.



Cliff

Re: Generator won't stay on

Posted: Tue Jul 28, 2015 2:51 pm
by lido14co
Here's the troubleshooting guide link: https://www.flightsystems.com/pdf/onan- ... -guide.pdf


Cliff

Re: Generator won't stay on

Posted: Tue Jul 28, 2015 9:59 pm
by Planck
There is a electric fuel pump that feeds the generator. You can pull the hose off the carb and see if it is pumping fuel when you try to start it, and if it keeps pumping after it starts. The fuse holder for the pump was faulty on my previous 91 B190. Replacements are available still at electrical supply shops. The fuse was good, but no continuity through the holder.

Re: Generator won't stay on

Posted: Wed Aug 05, 2015 9:13 pm
by Saprophyte
Thanks everyone for your advice!

Cliff, Thank you especially for that troubleshooting guide. I haven't dug into it much yet, but this guide is exactly what I need. I'm a mechanical engineer, I just don't have any experience with gensets.

Meanwhile, the plot thickens. Now the engine runs fine, but it won't generate AC. I don't think it's a combustion problem at all. This weekend I'm going to pull the generator and take my multimeter to that control board.

Andy