Onan generator problem

[DIYBob]

I have a problem with my Onan 5.0 BGRF26100P generator and hope someone has a suggestion. I hold the start button down and the generator starts, and when I let go of the button it quits. A mechanic said to put in a new circuit board but that didn't help. Any ideas?

Thanks.

[mjp]

Here is a link to some documentation http://www.flightsystems.com/pdf/onanrvtshootgd608.pdf which describes your question on page 6.

"Q. Why does my generator start and then shut down as soon as the start switch is released?

A

. Most models require both oil pressure and AC voltage from the generator to keep running. A lack of AC voltage can be caused by a variety of problems involving the control board, regulator, generator and wiring. A stuck oil pressure switch can also cause this symptom. The interaction between the various components of the system can be confusing during troubleshooting. Use the Troubleshooting Guide to isolate the problem."

I'm sure you have checked all the basics. Can be as simple as a defective oil pressure switch.

Safe Travels

[DanMichSr]

I thought mine had a bad board also, but it was so flaky in what it would do under different circumstances. Sometimes it would start by itself, sometimes not at all. Sometimes the red light would blink and it wouldn't start at all but I would pull the connection off on the left of the Onan and then it would start, but after I traveled any distance it would act up again. Now all is ok. It was a long process but they finally figured it was a wire that was stripped back to far and then crimped and attached and that would hit on metal on cause my problems. They took pictures of it and sent it to the factory in Indiana and it was under warranty and they paid for my gas to get it fixed. Just a thought since there were no replies.

[4Knights]

I had this same issue with my Onan 7kw Marquis, not wanting to pay $90/hr for someone else to do what I could try figure out, I found one wire (many hours,ok days later). that was broken.
, the wire was all they way in the back and only found it by using a mirror, flashlight and removing all the covers I could remove. I also had the help of an online gen mechanic named Hank from just answer .com Anyway, you can figure this out, call Onan and they will send you the schematics.

[mr300ce]

Only had my Bounder for a few months. Thought I better run the generator for a few minutes to keep things oiled, etc. It would start, then die, start, die. Hmph ??

Looked down at console and saw fuel gage at 1/4 full. Remembered reading in owners manual that gen would not run below 1/4 so as not to use up all the fuel, and thus strand you where you sit.

[jfran304]

Sounds like what my 7.0 does when I'm low on gas. It will start and then die when I let go of the switch. You can also have the same problem if you are on a slope and the fuel in your tank is low and doesn't reach the pick up hose.

Good Luck,
Jon

[RVhauler]

My Onan 6.5K would only run as long as starter switch was held in. Onan tech went straight to brushes. They had a build up around them. Tech cleaned the area. Removed brushes and checked them for servicability and cleaned then, He further polished the armature and reassembled. No more problem for over two years. Cost aprx $100 labor

[mr300ce]

Quote:

Originally Posted by RVhauler My Onan 6.5K would only run as long as starter switch was held in. Onan tech went straight to brushes. They had a build up around them. Tech cleaned the area. Removed brushes and checked them for servicability and cleaned then, He further polished the armature and reassembled. No more problem for over two years. Cost aprx $100 labor

This does not make sense to me. Brushes are in the 'starter', so if it started then died when the button was released, the starter was working fine. Sounds like a relay was not working, thus killing the gen when starter button released.

[4Knights]

Quote:

Originally Posted by mr300ce This does not make sense to me. Brushes are in the 'starter', so if it started then died when the button was released, the starter was working fine. Sounds like a relay was not working, thus killing the gen when starter button released.

I think he's referring to the stator brushes in the genset itself, when I had my troubles the manual described removing them and using a dowel with scotch Brite on the tip to clean them off. Something about the stator electricity feeding / completing the circuit for the gen set to stay running. Not a mechanic but did find a wire that did just that ( came from circuit board into gen) it was broken, once fixed gen started right up.

[DIYBob]

Thanks for all the ideas. Haven't had time to check them out and won't be able to until the weather warms, but I'll report back.

[a k]

I thought mine was going off on high temp or oil but I found it was due to no voltage coming from the exciter(slip rings). Mouse got in and built a nest. Ran me nuts, but cleaned it out and scotched bright the slip rings and hasn't failed since. Most generators will give you a code by a blinking light on the start button. Battery voltage goes direct to the slip rings(exciting the stator) and when it gets up to speeds it multiplies it and that tells the regulator all is a go. If it doesn't ramp up it won't run, but it will run if you hold the start button down.