Generator hiccups

[Mr__Pinky]

We were returning from a 6000 mi. plus trip in our DSDP about 3 wks. ago, driving through Arizona and southern Calif.. Our Onan 7500 would run about 15 to 20 minutes and then die. It had worked previously on this trip with no problems. I had it serviced shortly before leaving on this trip, oil change & filter, etc.. The technician mentioned that he did not change the fuel filter because it was hard to get to and wasn't necessary because the chassis fuel filter did all that was required.

I might mention that when we had the problems with gen. not running, it was a toasty 116 deg. outside. Could it be that the gen. just got too hot and quit? The dash air alone isn't enough to make it bearable inside an RV when it is that hot!!

I tried it again when it 'cooled down' to about 98 deg. the next day and it worked fine. I checked the coolant, oil etc. and everything was O.K.

Any ideas?

[WyoTraveler]

My 5500 generator struggled in over 100 degrees from Spokane to Missoula MT. It is hot out there.

[JackMS]

Thanks Ranger. But I got the cheap mh, no slide on gen. I've had it out twice before, about 30 minutes once I gather tools. I slide it out onto a forklift and take it in the shop. I had it out about a year or so ago to change temp sensor. Did thermostat and water pump belt, new antifreeze. I think I found a problem. The 3 hoses going to radiator cap are so long it is hard to get them inside without kinking them they were kinked and my water was low. May be OP's problem also.

[Jamboree89]

Just did my annual service on my 7500QD. I also removed the generator top cover and cleaned the radiator on it. The way the radiator is angled it is a perfect trap for leaves, grass clippings, etc. picked up by the cooling fan. Suggest you add generator radiator cleaning to your annual schedule.

[Ranger_Smith]

JackMS wrote:

Ranger Smith wrote:
Generator fuel filter. The generator feed comes right from the tank I believe and NOT the chassis filter. I changed mine the other day in about 15 minutes.Drop inspection door, remove 2 lines, remove nut, reverse procedure.

Exactly. Same on my holiday rambler. Separate supply and return lines for engine and gen. Otherwise gen would not shut off at 1/4 tank and engine stay running.

Could also be overheating. I have a water temp gauge on mine and yesterday it just kept climbing. I stopped and turned off both a/c's and it cooled back down. It shut down on me Thursday while I was in the house packing so didn't see the temp but pretty sure now it was overheating. Going out now to start the gen removal process to find out why.

No need to remove the generator. If yours is on a slide out the front just slide it out and remove top. Have access to radiator,thermostat and everything else. Check the overflow bottle. Mine had algae in it and it actually plugged the hose where it puts more water in the radiator if it gets low.

[JackMS]

Ranger Smith wrote:
Generator fuel filter. The generator feed comes right from the tank I believe and NOT the chassis filter. I changed mine the other day in about 15 minutes.Drop inspection door, remove 2 lines, remove nut, reverse procedure.

Exactly. Same on my holiday rambler. Separate supply and return lines for engine and gen. Otherwise gen would not shut off at 1/4 tank and engine stay running.

Could also be overheating. I have a water temp gauge on mine and yesterday it just kept climbing. I stopped and turned off both a/c's and it cooled back down. It shut down on me Thursday while I was in the house packing so didn't see the temp but pretty sure now it was overheating. Going out now to start the gen removal process to find out why.

[Ranger_Smith]

Generator fuel filter. The generator feed comes right from the tank I believe and NOT the chassis filter. I changed mine the other day in about 15 minutes.Drop inspection door, remove 2 lines, remove nut, reverse procedure.

[RognBon]

Get a new tech. I had the same issue on my 7500QD and it was a plugged generator fuel filter. Changed the filter and no more problems.