Community Forums

Colesmeister · 05-21-2008, 05:49 AM

We have a 2000 D with the Onan 7500 Quiet Diesel generator. This morning I got up at 5am and the generator was running. I went out and shut it off. Later in the morning, I went to my favorite coffee shop and when I returned, the generator was running again.

This has happened at least three times before.

I know some generators turn themselves on when the batteries get low, right? I don't think I have one of those, but how do I tell? And even if I have a self-starting generator, all the batteries in the rig were replaced about six weeks ago.

Any help you can give will be greatly appreciated.

Greg

Colesmeister · 05-21-2008, 05:49 AM

We have a 2000 D with the Onan 7500 Quiet Diesel generator. This morning I got up at 5am and the generator was running. I went out and shut it off. Later in the morning, I went to my favorite coffee shop and when I returned, the generator was running again.

This has happened at least three times before.

I know some generators turn themselves on when the batteries get low, right? I don't think I have one of those, but how do I tell? And even if I have a self-starting generator, all the batteries in the rig were replaced about six weeks ago.

Any help you can give will be greatly appreciated.

Greg

Rick Long · 05-21-2008, 07:28 AM

Ok.. I can see everyone else is afraid to tell you.. soooo..

It's a ghost... Yep.. it's the infamous RV Ghost. It travels around from RV to RV, pulling little pranks. Nothing serious, just little things to annoy us or keep us on our toes. Don't worry.. it'll leave shortly.. It likes to be on the road.

Jack Myton · 05-21-2008, 07:52 AM

When an Onan Generator starts by itself, especially one without an autostart, it must be caused by the shorting, perhaps by moisture in the wire harness connection, although there are still many who believe in ghosts, eh. Our Onan 7.5 Quiet diesel in our '07 Revolution did the same thing. We park our coach next to our home, and last winter. on two separate mornings, the generator was clicking away, self priming, trying to start. I thought it was the autostart that was set to manual, and simply pulled the wire harness plug apart at the firewall. This Spring I took it to Cummins for a faulty autostart. They never really found a problem with the autostart. I am convinced that is moisture getting into the wire harness plug in front of the firewall. It is fairly open to the elements. Make sure the connection is tight and then wrap or seal it to keep out moisture and I bet you'll never have another problem.

Route 66 · 05-21-2008, 08:21 AM

Jack is correct.

If you search on this issue, you will find others have had the same problem.

phays · 05-21-2008, 05:05 PM

I too had my 7.5kw gen autostart on my 98 Vectra. Suggestions were to clean the control connection wiring socket and put dielectric grease on the connection. I did both and haven't had a problem since. But, I don't know if it is fixed.

I called Onan and was told that the problem is a circuit board inside the generator. About an hours labor to install board unless your generator is like mine and not on a slide. Then the generator has to be removed adding about 2 hours labor for removal and reinstalling.

I asked if this was a common problem and was told it happens to some generators but not a chronic problem. I am skeptical of that answer but apparently Onan isn't going to to anything to help us.

I am considering a cut-off switch to the the starter for the generator. If you are going to be away from the RV and can afford to not charge your house batteries, you can disconnect the house batteries.

Bob (WA0MQE) · 05-22-2008, 03:57 AM

Did you buy the motorhome new, or is it used? If it's a used rig, maybe someone installed an Inverter that has the capability you mentioned. My inverter I have on our motorhome has the ability to start the generator when the batteries reach a set voltage. I don't normally use this feature, so I have it turned off at the present time.

JoeT · 05-22-2008, 09:13 AM

Mine started a couple of years ago while I was out of town. I called Onan and they toled me is is almost always caused by animals. When I looked at the generator it had cat tracks on top of it. (I have an outdoor cat)
I wedged a piece of wire under the starter switch on the generator and it never started by itself again until last week. I had removed the wire doing maintenance and didn't replace it.

Do you have a cat?

Colesmeister · 05-22-2008, 10:03 AM

Thanks for all the responses. I called Onan and they mentioned that some inverters can turn on the generator if the batteries get low. I'll have to research this whole thing a little more.

Joe: Yes, we have six cats!

As a first step in solving this, I think I'll take a look at that switch and see what I can do to keep feline paws from activating it.

Greg

Don (W5IT) · 05-23-2008, 02:42 AM

Greg we had a Discovery with the 7.5 Onan. Like Joe, we had a "Garfield" (Fat Cat) that was and outside cat.

I found the generator runing a few times and could not figure out why. I unplugged the remote harness and it still would "Self start" (Or so i thought) every once in a while. It was driving me crazy. (Well more so than "Normal"

)

One day I was outside when it "Self Started". VERY soon after it "Self started" I saw "Garfield" runing away from the rig like a scalded dog was after it. I wedged a folded up piece of paper under the switch and it never happened again. (I did the same on our other coaches after that)

Zimectrin · 05-26-2008, 05:55 AM

I like the cat idea.

....And all this time thought this was an undocumented feature.

Ecker · 05-26-2008, 11:43 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Colesmeister:
We have a 2000 D with the Onan 7500 Quiet Diesel generator. This morning I got up at 5am and the generator was running. I went out and shut it off. Later in the morning, I went to my favorite coffee shop and when I returned, the generator was running again.

This has happened at least three times before.

I know some generators turn themselves on when the batteries get low, right? I don't think I have one of those, but how do I tell? And even if I have a self-starting generator, all the batteries in the rig were replaced about six weeks ago.

Any help you can give will be greatly appreciated.

Greg </div></BLOCKQUOTE>
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This issue was quite common on D's of that era. It was caused by moisture coming down off the air duct above the generator and shorting the circut board/switch. If you belong to DOAI you can find a lot of discussion on this in the TIPS section of web site.

Jack Myton · 05-26-2008, 03:27 PM

I have a real hard time believing that an animal lighter than giraffe could step or lay on the button and hold it down for several seconds, long enough to start a generator. I have my money on moisture, eh.

Bamm Bamm · 03-04-2020, 08:40 AM

I too am having an issue with my 7.5KW Onan self starting. It only does it when it has been raining. I am sure that it is a moisture issue. Most of the time putting a sheet of plastic over my generator will stop it from happening. Quit frustrating and I am sure that my neighbors cant stand it when it comes on at 4 am.