Community Forums

corprimo · 12-22-2020, 12:26 PM

When the Temperature sensor fails, can it work intermittently? A month ago, while driving from WA to Tucson, our Alternator went out on our Cat C7 engine, so we fired up the generator. It ran for a few hours, then quit. It would start up again, but only run for about a minute - showing codes 1 and 33, for "overheating" which it probably wasn't. That evening, topped off generator coolant, and in the AM, 40 degrees outside, genny started right up, and quit after a minute with same codes. We had Alternator replaced in Fresno and continued to Tucson without using generator. Yesterday, I started up the generator to confirm it was going to need repair at a shop here in Tucson, and it ran just fine with full load for 30 minutes. There's no point bringing in to be fixed if they can't duplicate the problem. Once we get back to Washington in the spring, I can probably drop the generator and fix it myself, but I'm wondering if those sensors can sometimes work and sometimes not. Or it could be something else...

Mile Marker 42 · 12-22-2020, 12:31 PM

Quote:

Originally Posted by corprimo

When the Temperature sensor fails, can it work intermittently? A month ago, while driving from WA to Tucson, our Alternator went out on our Cat C7 engine, so we fired up the generator. It ran for a few hours, then quit. It would start up again, but only run for about a minute - showing codes 1 and 33, for "overheating" which it probably wasn't. That evening, topped off generator coolant, and in the AM, 40 degrees outside, genny started right up, and quit after a minute with same codes. We had Alternator replaced in Fresno and continued to Tucson without using generator. Yesterday, I started up the generator to confirm it was going to need repair at a shop here in Tucson, and it ran just fine with full load for 30 minutes. There's no point bringing in to be fixed if they can't duplicate the problem. Once we get back to Washington in the spring, I can probably drop the generator and fix it myself, but I'm wondering if those sensors can sometimes work and sometimes not. Or it could be something else...

Had similar issues with my 7500. Remove power from under the generator. Disconnect both positive and negative cables for 30 min. Wire brush terminal ends and mounting studs. Reconnect. Hold down start button for 60 seconds, then start generator. This fixed my temp sensor code.

ernieh · 12-22-2020, 12:48 PM

I had an issue with the QD8000 on my previous coach. Throwing various codes including temp. Had it into Cummins and they found nothing, but I continued to have intermittent problems. Finally, I found a ground stud down near the starter. It must have had 10 wires attached but the nut wasn't even finger tight. Tightened it up and had no further issues.

vseasport · 12-22-2020, 02:53 PM

Quote:

Originally Posted by corprimo

When the Temperature sensor fails, can it work intermittently? A month ago, while driving from WA to Tucson, our Alternator went out on our Cat C7 engine, so we fired up the generator. It ran for a few hours, then quit. It would start up again, but only run for about a minute - showing codes 1 and 33, for "overheating" which it probably wasn't. That evening, topped off generator coolant, and in the AM, 40 degrees outside, genny started right up, and quit after a minute with same codes. We had Alternator replaced in Fresno and continued to Tucson without using generator. Yesterday, I started up the generator to confirm it was going to need repair at a shop here in Tucson, and it ran just fine with full load for 30 minutes. There's no point bringing in to be fixed if they can't duplicate the problem. Once we get back to Washington in the spring, I can probably drop the generator and fix it myself, but I'm wondering if those sensors can sometimes work and sometimes not. Or it could be something else...

I wouldn't be surprised if your generator is over heating. Mine would run for 45 minutes under full load before throwing code 33 and shutting down. It was hard to believe it would take that long to over heat so I pulled the thermostat and checked it in hot water on the stove with a thermometer. The stat work properly and so did the temp sensor shutting down the unit. Flushing the block solved the problem.

You will need to start somewhere to find the problem. Verifing your not getting hot is a good place.

radar · 12-22-2020, 03:02 PM

Quote:

Originally Posted by corprimo

When the Temperature sensor fails, can it work intermittently? A month ago, while driving from WA to Tucson, our Alternator went out on our Cat C7 engine, so we fired up the generator. It ran for a few hours, then quit. It would start up again, but only run for about a minute - showing codes 1 and 33, for "overheating" which it probably wasn't. That evening, topped off generator coolant, and in the AM, 40 degrees outside, genny started right up, and quit after a minute with same codes. We had Alternator replaced in Fresno and continued to Tucson without using generator. Yesterday, I started up the generator to confirm it was going to need repair at a shop here in Tucson, and it ran just fine with full load for 30 minutes. There's no point bringing in to be fixed if they can't duplicate the problem. Once we get back to Washington in the spring, I can probably drop the generator and fix it myself, but I'm wondering if those sensors can sometimes work and sometimes not. Or it could be something else...

Yep. That’s exactly what ours did. We couldn’t get to our temperature sensor easy because we don’t have a slide out generator. So we hay wired a second sensor on the road hose and put a two way switch on it to cheat the original. It goes through a check at one minute and then again at 4 minutes. After that it doesn’t check that logic input. This happened 10 years ago. Since then we have a whack more hours on it. But we still have to chest it at start up.

If you have a pull out generator it’s easy to get to and change. Many people break the old one coming out though so be ready for some screwing around to get it to unscrew.

Cheers.

corprimo · 12-22-2020, 11:08 PM

When this started acting up a month ago we drove a hundred miles to our reserved campsite with no alternator and the generator only running for one minute at a time. When voltage got down to 12, I’d fire up generator for a minute of charge. Probably did that 30 times before we could plug in to shore power. In the morning, 40 degrees outside and it still quit after 1 minute. We drove 60 miles to FL in Fresno restarting generator a bunch more times. Got Alternator replaced there at $172 per hour. Generator only has 450 hours on it, but is 16 years old. We’ll be parked here in Tucson for 2 more months, so no hurry. I’ll try the wire disconnect/wire brushing. Thanks all!