Is it possible for a generator to start itself?

[jayhawk1]

Sounds crazy. But it happened. I have a 2005 M-4304 Mountain aire with a onan 7500 generator. It was parked under a awning and was plugged into 50 amp service. Doors were locked. A thunderstorm came through last night, not much lightning. This morning when I went outside the house I heard the generator running. How can this happen?
Nothing seems wrong, everything seems to work ok.
Has anyone else had this happen? Could my generator switch have shorted out? It seems ok now.

[RJay]

The short answer is yes. The harder part is to try to explain it. Not knowing the circumstances of the storm, what you had running in your coach and what electrical features you have in your coach.


If instead of finding your generator running you found your entire electrical system burned up and you filed an insurance claim, that could set off a forensic investigation by the insurance company that could take weeks; and if no smoking gun was found the best you could hope for would be the most likely cause.

[bigskymt]

Last year I experierenced the same thing. I was within 50' of our KSDP w/ Onan 7.5 when I heard it crank over and start. I thought my wife had started it.........nope, she was nowhere near.
A call to Onan and they suggested the wiring terminals where the remote connects were wet and had shorted, nope, we'd been in the desert for 4 weeks.
I turned it off normally and it never happened again.
It's still a mystery to me..............thanks for your report that helps to confirm my sanity.

[Dave and Jaime]

Quote:

Originally Posted by jayhawk1 Sounds crazy. But it happened. I have a 2005 M-4304 Mountain aire with a onan 7500 generator. It was parked under a awning and was plugged into 50 amp service. Doors were locked. A thunderstorm came through last night, not much lightning. This morning when I went outside the house I heard the generator running. How can this happen? Nothing seems wrong, everything seems to work ok. Has anyone else had this happen? Could my generator switch have shorted out? It seems ok now.

Do you know if your unit has AGS (Automatic Generator Starting)? That would explain it.

[jayhawk1]

We had a downpour for a few minutes. I suppose the wind could have blown some rain through the grill and on to the generator, even though the entire rig was under the awning. The only thing that was running on the inside was the refregerator. The a/c, heater, water heater and pump, and satellite system were all off. Thanks for the help Bob.

2005 Mountain aire 4304--2008 Acadia tow- 1 Boston terrier

[Route 66]

Quote:

A call to Onan and they suggested the wiring terminals where the remote connects were wet and had shorted

We've had several members reporting this as the cause of their problem.

[jayhawk1]

I will have to check on the AGS Dave. But why would that make a difference if the coach was plugged in and no real demand for electricity?

[Gary - K7GLD]

Dunno if it's in any way the case here, but we had missionary friends in South Africa, where their compound was powered by a large diesel generator. They often had horrific lightening storms there - and it was quite common for the induced electrical current from the overhead lightening to spin the generator over, even though it had earlier been shut down.

I suppose if an electrical storm was powerful enough, and there was enough wiring "antenna' connected to the generator at the time, it possibly could spin over and start?

[Norm4015]

Three of my friends and I have all had the same problem. The connector between the generator and the wiring inside the motorhome gets moisture in it or corrodes and it causes the generator to start. Look at your generator and you will see a wiring cable coming out of the upper left side. Follow it to the connector that goes inside the motorhome to the switches and meter (if you have one).

Disconnect that connector and spray both sides with electric cleaner, then coat the pins with di-electric grease to seal the connections. You will never have the problem again. I have talked to several people with the same problem and fix and none of theirs ever failed again.

[jayhawk1]

Thank You! I will try that.

[Dave and Jaime]

Quote:

Originally Posted by jayhawk1 I will have to check on the AGS Dave. But why would that make a difference if the coach was plugged in and no real demand for electricity?

I have AGS and my generator has started before when plugged in. There are a host of possible reasons for that, such as a bad battery that is not allowing a proper recharge so the AGS kicks in when voltage is low. Also, on my coach, the AC/Heat thermostat can be set to come on via AGS when the temp is too high/low. Having AGS simply complicates the troubleshooting part.

["007"]

Some people have found that behind the face plate where start switch is mounted it will get corrosion over time and short the components and requires some contact spray cleaner to correct the problem.

[bigskymt]

..............Sorry, I've not learned how to insert quotes yet.........
At the recommendation of Onan I inspected the I/F connections to the remote and on board starter switch. Both were clean and dry, the connections at the remote showed evidence of some kind of oily substance.
In any event I'm at a loss to explain the uncommanded start I witnessed.
I'm wondering how 12VDC can arc across contacts with sufficient current to heat glow plugs and energize a starter. It happened once and never again in spite of rain storms both driving and parked.
I hope this thread continues with more ideas.