Onan 4000 Generator Shuts Off While Driving in 2025 Minnie Winnie 25B

[MARK88]

I just got a new 2025 Minnie Winnie 25b, I have had it 4 months, and the generator still does not work. I have taken it to Camping World 3 times and Cummings 2 times. The Generator will start and run fine, but when I drive it shuts off. I dont think Camping World or Cummings have a any clue how to fix it. I call Winnebago, and they are zero help. Should I take it somewhere and payout of pocket, get a lawyer? I have made 4 payments, and still I dont have a working unit.

Mark

 

[creativepart]

Sorry you're having issues. First, forget getting a lawyer that will just waste time and money. Obviously, skip Camping World. Their reputation is below any trust for repairs. Cummings on the other hand is the manufacturer and they are the responsible party.

I had a Forest River Class C 10-years ago and it did the same thing. Cummings kept it for a week. They ran an entire tank of gas out of the RV running the generator in the parking lot for days on end. It never once stopped for them. But anytime I drove it in hot temps -- 95 to 105 it would die while driving. Sometimes it would restart but then die again until it just wouldn't restart. In cooler weather it would run without issue.

Shutting down while driving can be cause by too little oil, too much oil or too much heat. (or gas below 2/3rds of a tank). If this is happening in temperatures above 95 degrees then, you are probably seeing the latter. Certainly one of the service visits checked the oil level.

If it's too hot, about all you can do is drive somewhere with cooler temps.

RV's are almost always exempt from Lemon Laws and even if they weren't it wouldn't apply to something that doesn't prevent you from using the RV or involve safety issues.

Welcome to the wonderful but imperfect world of RV ownership. Most of us just learn to live with the imperfections.

 

[Eagle5]

Greetings Mark,
With my Onan 4000 generator, I add Sea Foam to my main fuel tank, at the rate of one ounce per gallon of gasoline. I believe the carburetors on these generators are extremely sensitive to the ethanol additives in fuel, and the Sea Foam keeps mine running well, and at a steady RPM. Without the Sea Foam, I believe the float in the carburetor's fuel bowl can get sticky, causing the fuel to surge even when not driving. Add-in the vehicle's motion, and the generator may momentarily starve for fuel. It might be the solution for you, and it might not, but it would be a fairly inexpensive experiment to try. If you keep your RV's fuel tank over ¼ full, it should keep working while traveling down the road, as long as the ambient temperature is below 122°F.
Welcome to the forum.
Eagle5

 

[pricejonnyb]

I just got a new 2025 Minnie Winnie 25b, I have had it 4 months, and the generator still does not work. I have taken it to Camping World 3 times and Cummings 2 times. The Generator will start and run fine, but when I drive it shuts off. I dont think Camping World or Cummings have a any clue how to fix it. I call Winnebago, and they are zero help. Should I take it somewhere and payout of pocket, get a lawyer? I have made 4 payments, and still I dont have a working unit.

Mark

Drive it - to Cummins while it is still in warranty, they found that Winnebago crimped the fuel line and had an inadequate ground. Some of the repair work wasn't under warranty but they replaced the carb and fuel pump under warranty. It runs!
Working with Winnebago on the other stuff. The dealer wanted $960 to remove the generator and work with Cummins.

 

[Hermes2]

What code is the generator showing when it shuts down? If it's a general code 36, it "might" be an overheating issue. This is not uncommon. When driving in hot temps with the generator going, it's possible that the hot air that supposed to cool the engine is being recirculated back into the cooling side. This causes the gas to percolate in the float bowl and causes fuel starvation and shut down.

There's a bulletin from 2017 describing this, and potential solutions. A duct that vents the hot air away from the generator. It may or may not apply to your system, but it may be worth checking.

Search for ONAN Overheating Issue MC-10154771-9999.pdf or try https://static.nhtsa.gov/odi/tsbs/2019/MC-10154771-9999.pdf

 

[RV_Lee]

My guess is its vapor locking due to heat. Mine will also shut down if its in direct sun on a really hot day.

First make sure its tuned for your elevation

Vapor lock

 

[bcoldpro]

I just got a new 2025 Minnie Winnie 25b, I have had it 4 months, and the generator still does not work. I have taken it to Camping World 3 times and Cummings 2 times. The Generator will start and run fine, but when I drive it shuts off. I dont think Camping World or Cummings have a any clue how to fix it. I call Winnebago, and they are zero help. Should I take it somewhere and payout of pocket, get a lawyer? I have made 4 payments, and still I dont have a working unit.

Mark

You say you are driving with your generator on?! Maybe there is a safety feature that shuts the generator off when driving. Hope I didn't misunderstand but I don't think I have ever heard of anyone driving with the generator on? What would be the purpose of that anyway? Does it stay running when you are stationary?

 

[RobertToby]

You say you are driving with your generator on?! Maybe there is a safety feature that shuts the generator off when driving. Hope I didn't misunderstand but I don't think I have ever heard of anyone driving with the generator on? What would be the purpose of that anyway? Does it stay running when you are stationary?

I run my generator, along with many other folks, while driving. It runs my air conditioner in hot weather, along with my fridge and electric hot water heater (save on propane). I can start and stop it as needed or wanted from the switch on my dash.

 

[Morich]

It's been a couple weeks and I wondered how the issue was going. Fixed or thinking it over?
When looking at funky things like this, I like to begin with sorting out some of the less complex things that can go wrong before going for the tough stuff! It takes fuel, fire, and air to run, so I might start checking those basics first as less difficult?
So how about taking a close look at things that can kill the engine. One is loose wires like on the spark plug? Anything on the engine that seems loose? A closer look at how air gets to the carb? Maybe a mouse has built a nest there? I found out a motorhome engine will not run very well if a chipmunk has stuffed the air intake full of acorns!
Maybe worth throwing a few dollars at a new fuel filter just to avoid the hard stuff?
Maybe something as weird as a choke setting that is loose enough to wander around while running?
It's that sort of thing that I find service folks are not too good at finding as they are not nearly as interested as I am!

 

[wahoonc]

Does your outside door have vents in it? I had another brand of Class C that did not. I added vents and my overtemp shutdowns went away. The air cooled generators pick up fresh air from the side and exhaust it out the bottom. When they put it in a compartment with no added ventilation it has to try and pull fresh air up from the bottom on the side, guess what IT'S HOT AIR! Cummins had a bulletin out on this, but apparently no one has read it. Try running it without the door on a hot day and I can just about guarantee you it will be fine.

Aaron

 

[creativepart]

Maybe there is a safety feature that shuts the generator off when driving.

Nope, that's not a thing.

It's perfectly fine to run your generator when driving. Perhaps because of where you live or RV you don't need to run the A/C when driving and so this isn't a common thing. But, for us in the Southern US it definitely IS a common thing.

 

[bcoldpro]

In almost 10 years of RV ownership and lots of time spent on this forum and elsewhere, I have never heard of running a generator while driving. First of all, isn't there a chance of an explosion
or fire when refueling? I've driven 7 hour stints and with a bag of ice in the upper freezer my fridge has stayed cool enough to keep my food in good shape. As far as AC goes, my dash AC has worked just fine. If you want to contain the cold air to the front portion of your rig just add a curtain type set up. Won't be changing my ways....

 

[wahoonc]

We live in the Deep South we are more likely to have the generator running than not while driving. The dash A/C can't keep the main part of the RV cool and there are people riding there. I don't know why there would be an increased risk of an explosion, you have a big engine in the front running constantly too. Yes it should be shut down while refueling, but plenty of people don't shut their cars down either.

Aaron

 

[creativepart]

In almost 10 years of RV ownership and lots of time spent on this forum and elsewhere, I have never heard of running a generator while driving.

It's a super common thing that you just haven't heard of. But none the less fine to do and something done by a majority of folks that live in hot climates.

 

[Morich]

When new to an issue like RV and only doing for less than ten years there are lots of things one may not heard about yet! There are lots of new stuff that have come around in the last ten years and I'm glad I've missed lots of them.
My first motorhome trip, it had no cruise control as we now know it. There was a cable gizmo down next to the driver's foot which one could set once highway speed was reached and it maintained the setting of the carb for a pretty course way to keep it set without having a foot on the pedal.
Not much help in hills though!
Yes, generator running on the road is a pretty common thing as the Rv gets bigger!

 

[SMH2026]

Hi,

On a new RV with genset shutting down I'd suspect the following:
Low lubricating oil check oil level
Fuel pickup installation problem. Pickup tube too short, improperly positioned, loose fitting, kinked line, or suction leak at a connection. Fuel slosh while driving exposes a marginal installation. Testing with a completely full chassis fuel tank is particularly useful.
Remote start/stop harness problem. Pinched or incorrectly routed harness intermittently commanding STOP as the coach moves.
Disconnect the remote-control harness at the generator, then operate the genset entirely from its local START/STOP switch. That removes the coach-side remote switch and its wiring from the equation.
The result is quite diagnostic:
Runs normally while driving with remote disconnected: fault is almost certainly in the remote circuit—pinched/chafed harness, connector/pin problem, defective remote switch/controller, or an intermittent STOP command caused by vibration.
Still shuts down while driving: remote circuit is essentially eliminated; move to fuel delivery/slosh, oil shutdown, generator wiring/grounds, airflow, etc.
Your debug can point the techs in the right direction.
I doubt that there's an overheat issue while driving due to airflow while underway.

Good Luck,
SM