Generator overheat problem...

[bsavage]

Okay, all you wizards of RV Land, we are traveling, left yesterday heading from AZ to Donner Ski Ranch (CA/NV border near Reno)... dry camping as we always do, rely heavily on 12,500 Onan gennie... worked fine for the three days before we left, about 2 hours into our journey the gennie shuts down (it's 112 degrees outside, give or take). Keeps shutting down. Pull off, have a look, Tony discovers it is quite low on both coolant and oil (we bought this coach in December, it's an '06, been on 3 outings so far with it, assumed it was fully serviced, our bad for not checking oil and coolant before leaving...) anywhoo... now it won't run for more than 5 minutes, then shuts down, fault code is overheat, we're now in the mountains of Northern CA where tonight it's in the 60's. Called Onan, called certified repair shops on the way, stopped at one, found that most of them will not go "in" to the gennie... seems like now its a faulty overheat sensor, cause it ain't overheatin' now!

So, does anyone know anyway to override a faulty overheat sensor, so it will get us through the weekend? And, if so, what and where is an overheat sensor? Or, does anyone have any other ideas???

Thanks in advance...

[bsavage]

Okay, all you wizards of RV Land, we are traveling, left yesterday heading from AZ to Donner Ski Ranch (CA/NV border near Reno)... dry camping as we always do, rely heavily on 12,500 Onan gennie... worked fine for the three days before we left, about 2 hours into our journey the gennie shuts down (it's 112 degrees outside, give or take). Keeps shutting down. Pull off, have a look, Tony discovers it is quite low on both coolant and oil (we bought this coach in December, it's an '06, been on 3 outings so far with it, assumed it was fully serviced, our bad for not checking oil and coolant before leaving...) anywhoo... now it won't run for more than 5 minutes, then shuts down, fault code is overheat, we're now in the mountains of Northern CA where tonight it's in the 60's. Called Onan, called certified repair shops on the way, stopped at one, found that most of them will not go "in" to the gennie... seems like now its a faulty overheat sensor, cause it ain't overheatin' now!

So, does anyone know anyway to override a faulty overheat sensor, so it will get us through the weekend? And, if so, what and where is an overheat sensor? Or, does anyone have any other ideas???

Thanks in advance...

[ronboc]

OUCH!

I always said: "I love the sound of a generator in the morning (afternoon, evening...)". I hate it when it isn't noisy. Sorry about the issues.

The genny is one of the few things I haven't torn into (yet), so I'm sorry but I can't help you there. I do know that it's all computer-controlled inside, but that's about it. have you taken the big cover off to look? Maybe a loose/broke/burned sense-wire somewhere?

Looks like you've done the right things so far. Have you called 24/7 Monaco-Tech Support? Is there a Coach-Care facility nearby?

{{I'm not even going to insult your intelligence as to ask if there's sufficient fuel in the tank, as most will cut out between 1/4-1/2 tank}}.

Please let us know how it goes.
Ron

[Tom N]

I don't think your generator is designed to operate in 112 degree ambient temperatures.

Have you reset the code??

RESTORING FAULT CODE BLINKING
The fault code stops blinking after five minutes.
Press Stop three times within three seconds to restore fault code blinking.

[bsavage]

Thanks for the input... yes, plenty of fuel, I called every cummings/onan shop on the way and no one could take it. Our gennie on the previous Beaver always handled the heat well...

[MonacoMama]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I don't think your generator is designed to operate in 112 degree ambient temperatures. </div></BLOCKQUOTE>


Well...for what it's worth... this gennie would NOT even run in 60 degree temps!

[Tom N]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MonacoMama:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I don't think your generator is designed to operate in 112 degree ambient temperatures. </div></BLOCKQUOTE>


Well...for what it's worth... this gennie would NOT even run in 60 degree temps! </div></BLOCKQUOTE>

Well.....before or after the overheating problem???

If before why mention the overheating.

If after the overheating possible caused your problem.

[SacsTC]

Overheating is the code given by the gennie after starting and running for approx 5 minutes and then stopping.
It has run faithfully in the AZ heat for over a year. It was running fine on Thursday on the way from AZ into Nevada. Thursday on the way into Nevada, it stops running with an overheat code.
Now only runs for approx 5 min no matter the ambient temp. Code continues for overheat.
By the way Tom, does your gennie run in high temps or do you just park and wait for the weather to change to something that suits you and your coach before you continue on your way????????

[Tom N]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SacsTC:
By the way Tom, does your gennie run in high temps or do you just park and wait for the weather to change to something that suits you and your coach before you continue on your way???????? </div></BLOCKQUOTE>

Wait for a change in the weather to something that suits me?????

We do most of our traveling in the Fall, Winter & Spring. Have never experience any temps even close to the reported 112 degree heat in this subject thread.

Actually, I read the 12k Onan manual online and it mentioned temps. Especially oil weights for temps such as 112. Onan does not recommend using the 10wXX oils at these high temps.

But now it seems her problem developed before she hit the high ambients temps.

The coolant system should be flushed every 2 years and a new pressure cap installed at that time. Also the spark arrest should be checked and cleaned. Not many do this maintenance chore. Instructions are in the manual.

-Tom

[Ed-Deb]

If you can access the area where the fan belts are...you might check to see if the belts are intact and the water pump isn't leaking, and the fan is turning.

If it is truly just a sensor issue then you should be able to find it somewhere near the radiator or thermostat housing. Most sensors (if heat related) are merely thermistors that change resistance values based on temperature. The trick would be figuring out the right value for an appropriate operating temp and placing a resistor into the connector removed from the sensor.

I would caution anyone on trying to override a sensor before insuring that there is no underlying factor creating the over temp condition. To "force" the genset to continue to operate by overriding the fail safe systems / sensors could cause a catastrophic failure that will cost substantially more to repair. It could also potentially void any warranty coverage.

Did you call this place to see if they could get you in for repair?

http://www.gotpower.com/index.html


Ed

[bsavage]

Thanks for the detailed info. We're on our way home now (see me sweating??!! )... will take it in asap in Phoenix. Got some good help from MonacoMama and SacsTC who came to visit us in Donner, plugged us into their Coach for a while to keep systems running and batteries charged. I'll update when we know what the problem is...

Thanks again to all, especially MM & SacsTC!

Brenda

[bsavage]

Well, here's the update. Took it to Cummins Rocky Mountain Southwest, they said it was the fan belt which we can't get to, they had to take the gennie OUT of the coach to access it, and it's a known issue, so they've retrofitted it with the fix... changed the two fanbelts to one with a serpentine configuration, which will be good for 1500 hours.

This is the 2nd known issue that we've had in our total of three trips in this coach. I don't understand why there is not a notification/recall process on these "known issues". Anywhooo, we're picking it up tomorrow.

[MonacoMama]

Glad to here it is all taken care of, Brenda...at least now you know you won't be having any more gennie problems for awhile!
How are the 4 pups?
(her dogs are so sweet looking.. .especially Millie!)

[bsavage]

Thanks MM... it's in for the rest of the repairs... doggies are good!