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patrickemb · 06-20-2021, 07:26 PM

On my 08 madp with the 10K onan/Kubota generator. Started my Gen Thursday morning about 10 not sure how long it ran before stopping may hour or so. Got a code 36. Restarted it and stopped again shortly after with the same code. Started it again and it ran till some time early friday morning. Not really sure the time I got up at 6 and it was still cool inside the coach. Started it again at 6 Friday morning and it ran no stopping till Saturday night at midnight. I wasn't there to check codes but had to give instructions to DE to restart it. Ran till I turned it off this morning about 10. Code 36 has numerous options. Doesn't narrow it down enough. I'm about 200 hours away from required fuel filter change. Thought I'd go ahead and change it tomorrow, easy to do. Anyone have this problem and have the answer to fixing it? With such long running time before shutting down it would take awhile to know if it's the filter was the problem or something else. It would help if it did it more often and you could try different things to make the repairs. I should add that the outside temperature was upper nineties during the day and 80's at night. Good old Oklahoma summer. I always put the front end cap with the Gen out to help with air circulation and to keep the engine a little cooler.

Thanks

NHRA225 · 06-20-2021, 07:31 PM

Just My Opinion But 10K's are a PITA to Diagnose on your own- Get to an Onan Repair Shop to save your Sanity !

Car1 · 06-21-2021, 05:49 AM

Quote:

Originally Posted by patrickemb

On my 08 madp with the 10K onan/Kubota generator. Started my Gen Thursday morning about 10 not sure how long it ran before stopping may hour or so. Got a code 36. Restarted it and stopped again shortly after with the same code. Started it again and it ran till some time early friday morning. Not really sure the time I got up at 6 and it was still cool inside the coach. Started it again at 6 Friday morning and it ran no stopping till Saturday night at midnight. I wasn't there to check codes but had to give instructions to DE to restart it. Ran till I turned it off this morning about 10. Code 36 has numerous options. Doesn't narrow it down enough. I'm about 200 hours away from required fuel filter change. Thought I'd go ahead and change it tomorrow, easy to do. Anyone have this problem and have the answer to fixing it? With such long running time before shutting down it would take awhile to know if it's the filter was the problem or something else. It would help if it did it more often and you could try different things to make the repairs. I should add that the outside temperature was upper nineties during the day and 80's at night. Good old Oklahoma summer. I always put the front end cap with the Gen out to help with air circulation and to keep the engine a little cooler.

Thanks

I ran into a similar issue with a Country Coach I had owned, that was always dependable. After all sorts of research, and experimenting to narrow down the issue of the generator stopping. I decided to replace the generator fuel pump. That cured it. I think under light load there is not much of an issue. As you load down the generator, as with an air conditioner, and a second air conditioner and battery charging, the fuel pump will not supply the needed fuel, and it shuts down. I suggest and considering the age of your coach, to replace your fuel pump including a fresh fuel filter. I think at this juncture, I would also get that fuel pump from Onan/Cummins instead of experimenting with a knock off. Just my thought.

patrickemb · 06-21-2021, 06:21 AM

Thanks for the replies. The cummins repair shop that's close to me is not a good one. So I won't go there. I'll probably do the repairs myself. I have one more 4 day run on the 4th of July. If I can get thru those days I won't really need to run my Gen for another year unless I need it for the a/c's while going down the road.

Rev. Roy · 06-21-2021, 11:28 AM

Code 36 simply means the engine stopped without a shutdown command from the control panel. This leads to the most obvious question; do you have over a quarter than of fuel? Sorry but I have learned to ask obvious questions. I would go ahead and change the fuel filter first. It is easy and will eliminate it if it doesn't fix the problem. As stated already, the second thing is the fuel pump which is most likely the problem, IMHO. If it is going bad, it will start but can't keep up with the demand when load increases. After that I would take it to a " good" Cummins repair place.

mikwallace · 06-21-2021, 12:11 PM

I had similar problems with my 10kw Onan diesel generator. It would sometimes run for hours, other times only minutes, and eventually not run at all. I too had code 36 each time. Fuel was good, new fuel filter; however, the fuel pump wouldn’t prime. Ran voltage check on fuel pump wires at the pump and had battery voltage when pushing the prime button on the generator. Straight wired fuel pump from 12v source and pump worked, generator would start and run fine with pump straight wired. But with volt meter connected to pump when trying to prime the voltage dropped to between 5-6v. The J1-24 wire from controller controls the fuel pump ground. Traced back to harness plug at the controller and found bad connection: sometimes it worked sometimes not! I wriggled the connector while holding the prime switch and pump began to run. I removed the plug, sprayed with Contact cleaner and coated with di-electric grease. Works great!!

Hope this helps.

Here’s some pictures. The coolant reservoir is moved out of the way to gain access to the harness connector.

Sorry the pics posted rotated??!!

patrickemb · 06-21-2021, 07:36 PM

Rev Roy and mikwallace thank you. Was raining today so I didn't get the filter changed. Thanks for the pics. I have spray for the connection to so I'll do that as well tomorrow if no rain. Will also order a fuel pump.

markpj23 · 06-22-2021, 10:25 AM

This is a common problem with this vintage Onan genset. Happened to us also.

Cummins service bulletin regarding the control board. Board heating issue shuts down fuel pump power. New board is available from Cummins but pricey. Others have direct-wired their fuel pumps as a work around.

Good luck.

mikwallace · 06-23-2021, 05:45 PM

Quote:

Originally Posted by markpj23

This is a common problem with this vintage Onan genset. Happened to us also.

Cummins service bulletin regarding the control board. Board heating issue shuts down fuel pump power. New board is available from Cummins but pricey. Others have direct-wired their fuel pumps as a work around.

Good luck.

Where can I find a copy of that service bulletin??

patrickemb · 07-02-2021, 09:25 AM

Finally changed the fuel filter. Didn't help. Ran from 5 last night till about 9 this morning. Seems to be occurring more often. Any one have a part # for the control board that's mentioned in the above post.

Car1 · 07-03-2021, 06:08 AM

Is there a reason you did not want to change the fuel pump?? At least try running with no load, and then add one device at a time until every AC appliance is running. See if loading the generator down with a sizeable load expedites a shut down. That would indicate a fuel supply problem-fuel pump. It could be, as mentioned, the control board. Again, considering the age of the generator, it will not hurt to change the fuel pump. It could be worse-at least it is not a DEF head. LOL

patrickemb · 07-04-2021, 06:24 AM

It has been a busy June and very wet. I have today and tomorrow that I will be using the generator. I won't be using the generator much till next June. After experiencing more shut downs I have noticed that it seems to shut down when there is no to very little load on it. Usually there are no a/c's running. It's almost like the idle isn't high enough when coming off a load. So I don't think it's a fuel pump issue. Could it be a governor issue? If it needs a adjustment how do you adjust it?

bobfrommaine · 07-06-2021, 04:01 PM

There's 2 things that will shut down a genset: low oil pressure and high water temp. The water temp sensor should only have one terminal and when it is NOT sensing high temp, a continuity check will show that as an open (high resistance). The oil pressure switch is normally open and closes when there is oil pressure. Additionally lack of fuel will cause the engine to shut down. Usually the symptom is the engine will slow and the monitor circuit will shut the engine down when the speed falls below a preset number (or above a preset number). So, if the engine is starving for fuel, it may slow down noticeably under load. If this is the case, change the fuel filter or fuel pump or both. If a good running generator on an older coach starts misbehaving, I'd recommend replacing the fuel pump and filter with it. It can be expensive to troubleshoot an intermittent problem, so you could save yourself lots $$ by doing things yourself. In my experience, Onan techs are well trained and should be able to troubleshoot and repair your genset in a reasonable time.

patrickemb · 07-06-2021, 07:50 PM

Made it home without any more shut downs. Will look for a fuel pump 1st, it's alot less expensive than a cpu board. I did fine a aftermarket board by flight system for have the price (500.00) of a oem.