Onan Generator Overheats and shuts down.

You shouldn't have to fix a new MH, but if all else fails, install a vent like this in the door pointed forward to force air into the generator compartment. Is there a way for the air to flow outward? If not, install a second one in the bottom pointed to the rear.

Perko Vent

Bill

moving down the road would suck air away from the gen, SO that tells me it would heat up siting still with NO AIR moving. I think some one fed you some bull ****.

If it's a design flaw, wouldn't all the Terra motorhomes have the same problem?

This can be a problem based on a few factors - Placement of the genset, ambient temperature, how hard it's working, and how fast you are travelling. I used to have this issue on ours. It would happen when the factors above caused it to overheat. My genset sits behind the front driver's side wheel. Coincidentally right behind the engine manifold. So it gets a lot of heat just from the engine, add to that the heat of the road, and if you are stuck in traffic you aren't moving air over it, on a hot day (85+) and finally, most entry MH's are poorly insulated so that the AC works non stop to combat the ambient temperature thus putting a constant heavy load on the genset, and it's bound to overheat. Simple solution for mine was to add 2 vents in the bin door - almost like floor vents, one with fins facing forward to route air into the genset bin, and one with fins facing toward the rear to allow hot air to escape. Thor paid to have my dealer do the fix. Aesthetically it looks factory. That was over a year ago and haven't had the issue since.

On our last trip a couple weeks ago it was 100 degrees in central Californis and our generator shut off as we were driving. Not unusual as it has always shut off when it got really hot and we were moving.

However when we got home it was about 105 degrees were we live and I fired up the generator to run the air conditioners while we unpacked the coach. It never did shut off even after an hour and a half.

My Onan 5500 brings in air at the bottom of the unit and it's my belief that the engine heat is causing the overtemp to shut it down. It sucks a lot of air when it is running.

My plan is to put a wireless thermometer at the air intake and see what temperature air is going into the generator while we are driving.

ArchHoagland wrote:
On our last trip a couple weeks ago it was 100 degrees in central Californis and our generator shut off as we were driving. Not unusual as it has always shut off when it got really hot and we were moving.

However when we got home it was about 105 degrees were we live and I fired up the generator to run the air conditioners while we unpacked the coach. It never did shut off even after an hour and a half.

My Onan 5500 brings in air at the bottom of the unit and it's my belief that the engine heat is causing the overtemp to shut it down. It sucks a lot of air when it is running.

My plan is to put a wireless thermometer at the air intake and see what temperature air is going into the generator while we are driving.

That is exactly my point. If you have a gasser and your genset is at the front of the coach, it gets all that hot air from the engine. Not to mention road temps and tranny. All compounds the issue. That's why I chose a solution to pull air from the side of the coach. Problem solved.