Generator won't run while in motion

Hello all, just wondering if anyone might have an idea why our ONAN generator will not run for more than 10 mins. while we are in motion. It runs fine when we are not moving. This is on a 2005 Coachman class C motorhome, with 50 hrs. on the generator. We have never had this happen with our 2 older motorhomes. I will take it to the dealer as soon as I can, but were just wondering if anyone has had this happen to them before. Thanks for any information you might give on this subject.


Senior Member
Generator won't run while in motion

Might the oil be a bit low? Low oil will shut down the set. Or, a loose lead to the oil sensor would do it also.
Generator won't run while in motion

Thanks C Nash and Kirk, I did check the oil and it was full, but I did not know to check for a loose lead on the oil sensor or the kill switch. The service center for So. Cal. is only open on week days and I can't take off work right now. Now at least I know what to look for. I will post as soon as I know what the fix is. Thank you again. Best Reguards, Terry
Generator won't run while in motion

Hello Kirk and C Nash, I finally got a day off, and took our rig in to Coachmen repair facility, what the young we talk to said was that wind could cause the generator to shutdown. 55 to 60 MPR, along with a strong head, or cross wind, may have caused this problem. Today, I started the generator, tunr the AC on and drove 40 miles to the repair facility, no wind, no problem. The generator on our coach is toward the front, drivers side, all our other rigs were drivers side, but in the rear. I plan to put an extention on the pipe facing rearward or clamp a wind defelctor on the pipe. What do you all think? Also, is it possible that a vacuum caused by wind could starve the air intake. If I learn more I will post again. Thanks for all your help, Terry
Generator won't run while in motion

Seems like your solutions are working on a "design" problem. I wouldn't think that MH would have an unknown design problem with the generator.

You're solution should be directed toward a "local" problem involving something about your particular installation. To explain, did someone install the generator on YOUR MH differently than on the 100's of others of like make/model/mfg?

You might be barking up the wrong tree with "extensions" to the original design.

And, what "pipe" are you extending/redirecting? The air intake for the generator's carb?
Generator won't run while in motion

I doubt the wind caused the problem. The only way that I can think of for the wind to cause a problem would be for the exhaust pipe to be pointing to the front of the coach. At 70 mph you may have a problem then. I think your dealer guy was whistling Dixie. You may have a power regulator problem or a circuit board problem that when a resistor or capacitor reaches a certain temp it seperates and shuts the unit down. Could be an ignition circuit wire loose and when it jiggles just right it cuts power. There also may be a temp sensor so that you don't overheat.
Generator won't run while in motion

Thank you all for your replies, after reading them,and giving it more thought, I think you are right about the wind not causing my problem. After all, we are talking about a exhast pipe that has at most an 1 inch opening, and as s.harrington points out does not face forward, or into the wind. When I last ran the generator, on the way to the repair facility, the AC was on for about 1 1/2 hrs., but the temps. were much cooler than in the summer when the problem occurred. I did turn the thermostat to the lowest level, but here in So. Cal. :cool: that may not have been enough to put much of a load on the generator. I did not mention that the power mirrors, the cab radio, and the power to our entertainment center, are all without power. All powered by the coach batteries, and the fuses are not not blown. All of them are being check by Coachmen. Thanks again for the help, and I will post when I hear from Coachmen.
Generator won't run while in motion

i'm a genset tech if you would give me the model number and whether its gas, lp or diesel i should be able to help

if the genset has a light in the start/stop switch it will flash a code
1 over heating
2 low oil pressure
3 service fault code - press stop three times and genset will give a fault code will blink first number blink-blink then pause then second number blink-blink-blink (code 23) then pause and will start over

also try unplugging the remote wires to the genset normaly a 5 to 6 wire plug next to the genset where the power wires or battery cable hook up this will rule out a bump short in the remote wires
Generator won't run while in motion

Thanks kg5388, and welcome to the forum. Our rig is in the shop for some repairs. Some paint and decal work that was not right, they said they would check the genset also. I did not write down the model number, or serial number yet but as soon as I get it back I will put them in the manual, and post them for you. It is a Onan, 4.0, gas powered though. Are you talking about the start stop switch on the inside of the coach or on the genset itself. I think the one inside the coach has a light in it but I am not sure. I want to thank you again for your post, that was something I did not know. I hope to pick the rig this week, if work alows, and I will post when I get it back.
Generator won't run while in motion

lol this doesn't have anything to do with the generator not running but when I read this It reminded me of the cars of yester year, a lot of those cars had gravity flow fuel systems and as we drove we were fine until we started up a big hill, and the engine would quit because their was no pump to keep the gas flowing so my dad would have to turn the car around and back it up the hill and then we would be on our way.LoL thought some of you might remember those day's. Later Jim
Generator won't run while in motion

the light will be on the genset but on some rv's the inside switch will have it to
if it is a 4.0ky genset disconnect the remote wires and with the genset running before it gets hot open the pannel and rock the genset in the housing we have seen some that will vibrate and rub a hole in the sparkplug wire which runs from the back side and under the genset
it can be routed different if this is the problem
Generator won't run while in motion

lol USMC, I've heard the stories about those old cars from my dad, grandpa,and my friend at work (84 year old) USMC Master Gunny Sgt. it brings a smile to my face to think of those days also. Thanks for your sevice to our country. Happy travleing. Terry
Generator won't run while in motion

Thanks kg5388, even if thats not my problem theres no telling how many folks this imformation might help, now or in the future. If I ever get my rig back, at least I have some things to check. Take care and keep your wheels right side up. Terry
Generator won't run while in motion

your welcome and when you get your rig back don't forget to get me the model number and i can help you more
Generator won't run while in motion

kg5388, I got my rig back, they kept it 3 months and still did not fix everything, but that's another story. I did get the model number, it is 4KYFA26100K, and the serial number is H040676626. Thank you again, Terry
Generator won't run while in motion

with the genset running reach in and shake the genset in the housing if it doesn't shut down then shut it down and remove the spark plug wire from the spark plug and wiggle it around and try to start it .do that a couple of times the ky has a bad habbit of rubbin a hole in the plug wire and shorts it out when you hit a bump
try pressing stop 3 to 5 times in a row and see if it will give you a 3 flash code then press stop one more time and see if it will give you another code