My onan 8000 quite diesel won't stay running. I'm new to my 2016 seneca, I got it this summer but have not used it yet as we only go south in the winter. Purchased it from a private person and all worked well. Mid summer I was going to exercise it and it just died. My thinking it just ran out of fuel, it was below half a tank and no big deal because everything needed servicing anyway. I change oil and filter, new fuel filter, and air filter, primed it several times with no luck of starting. I took off the return fuel line and pumped a half gallon of fuel out also. I saw the positive cable look green so i put a new crimped end on it. A side point is I also put new house batteries in. It starts and runs only for 3 seconds, blink code is 36. It has an energy command 30 in house that only light up the few seconds it runs also. Not sure what to check next?
I had read in the past on some other forum that I don't use anymore where this occurred and that the manual suggested checking the fuel supply. The 36 was seen and it turns out that 36 just means the shutdown wasn't expected, which most often means a fuel issue.
In any case, the one I remember and particular to the Onan diesel generator is that the RV'r had the exact symptoms (similar) that you reported and decided to run a 12v wire directly to the fuel pump, applied power, turned on the generator and the generator ran without an issue. This lead to him replacing the main control board in the generator that supplies the fuel pump power which resolved the issue. He had mentioned that he visually observed damaged capacitors on the board. (perhaps you may want to look at the board as your next step).
Again, my information is just for what it is worth. I have a great memory fortunately, but sometimes what I remember isn't what I thought I remembered... lol. ~CA
thanks, Tomorow morning I will try to power the fuel pump and see if that works. This is my first seneca, I had a couple of pushers, and the generator was on a slide out in front. Is there a slide out kit for them, It's not a very easy job servicing this generator.
still no luck, I can hear, and feel the fuel pump does run even after it fires for a couple seconds. I also checked and replace the 3 fuses under the radiator cap cover and no luck. It sounds like it's under load when it does try to start, but I do have the breaker off. How do you access the circuit board?
Hopefully someone with more direct experience will chime in. I would expect to find the board under the cover(s) in the area boxed in red, and likely close to the star. I would follow any harnesses and connections in this area and see if any terminate at a circuit board. I would very carefully check all the connections and visually look at the board(s) for any components that look damaged. Perhaps take photos and look closer on your computer with a close up view. A capacitor could fail in a shorted condition (many\most fail open) and in a shorted condition, that short certainly could cause the load on the generator as you described when starting the generator.
However, there is no service manual on this link, but there is an install and owner's manual. It would be helpful if you could find a service manual, and sometimes a parts manual will indicate where everything is located. If you can find and share your exact model number, I will take a look and see if I can find a service manual, however they are generally not shared on the internet as companies sell them instead. Sometimes (many times) a similar model will have a similar service manual, not exact but possibly close enough to provide further guidance. ~CA
Thanks , I did get the cover off on the side of the generator and it did expose the ground wires, very green and rusty. I cleaned most of them up, still trying to get one off without breaking it, as of now still no luck. The black cover that holds the breaker and start switch look almost impossible to get off without taking out the unit. About a week ago I posted a question while working in the bedroom about the auto transfer switch so noisy, buzzing. Could that be the issue, but by shutting the main breaker off on the generator that should break that connection correct?
Location: Kingman AZ and where our Seneca is today.
Posts: 3,114
Quote:
Originally Posted by Kbraun
still no luck, I can hear, and feel the fuel pump does run even after it fires for a couple seconds. I also checked and replace the 3 fuses under the radiator cap cover and no luck. It sounds like it's under load when it does try to start, but I do have the breaker off. How do you access the circuit board?
I found another manual... But the forum won't allow it to be uploaded... DM/PM your email address and I will send it to you.
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Steve & Stacy with Jasper (Australian Cattle dog)
2015 Seneca 36FK
Custom 27' flatbed trailer hauling:
07 Toyota FJC & Yamaha Kodiak 400 ATV
With the generator breaker being turned off, the transfer switch shouldn't be of any concern regarding the issue you are having. Was the buzzing sound heard only when the generator was running? If so, there could be a relationship, but not a close enough relationship that would indicate the transfer switch is the cause of your issue (especially with the gen breaker turned off). ~CA
If you register on Cummins Quick serve you can look at various manuals. I don't think they have actual service manuals but they do have parts manuals and drawings to show where everything is located in the unit. You can load your engine and generator serial numbers in and all associated manuals pop up for you to review
Could be air in the injection system. I would try bleeding the air out of the injectors. Open all injectors lines 1/2 turn at the injector pump first and crank and crank, then tighten and do the same at the injectors. Or try one at a time. Might have to do a few times. Mine did the same and it finally stayed running and has been fine ever since.
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Chris and Erika
2019 Seneca TS towing 24' ATC Trailer
Thanks for all the help. Since this rig is new to me, and I tried everything in my ability I decided to pull it out and take it to a certified onan repair center in Sioux falls SD. To get a look at the boards you needed to get it out anyway, and after seeing how corraded the ground cables are I thought it best to have the experts fix it hopefully right. Jayco could have done a better job of placement and accessibility of the generator, not please with that so far. I live in SW Mn. so my choices were Sioux falls or the twin cities for service centers, I opted for SD for many reasons. I will keep you posted on what they find, unless it was something very stupid on my part, thanks again.
Thanks for all the help. Since this rig is new to me, and I tried everything in my ability I decided to pull it out and take it to a certified onan repair center in Sioux falls SD. To get a look at the boards you needed to get it out anyway, and after seeing how corraded the ground cables are I thought it best to have the experts fix it hopefully right. Jayco could have done a better job of placement and accessibility of the generator, not please with that so far. I live in SW Mn. so my choices were Sioux falls or the twin cities for service centers, I opted for SD for many reasons. I will keep you posted on what they find, unless it was something very stupid on my part, thanks again.
Could you share the details on how you got it out? Thanks.
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Dave & Patricia
2017 Seneca 37FS
2016 Toyota Highlander
Kar Kaddy SS
I didn't take any pictures on taking it out, but it was fairly simple, but it is a 2-person job. It also requires some heavy lifting help; I used my skid loader with forks and a pallet set at the same height as the generator and slid it on after it was all loose. Basically, the power cables, positive and ground need to be removed, I took the positive cables, 2 of them off at the batteries first for safety. Then the fuel lines, also 2 of them, make sure to label what goes where. After that there are 4 bolts holding it down you need to impact out, all 4 of mine snapped off because the generator frame is aluminum, and the bolts are steel and after time they don't like each other. I'm having the shop get the broken pieces out. Then we just slid it out a few inches to get at the back side where the wires are. 2 set of wires, 1 with a weather pack plug, just unplug, and another in a flexible Romex cable that goes into the switch box under the bed. 5 wires in it need to be disconnected and be sure to label them. After that we just slid it on the pallet and loaded it into my pickup, fairly easy but it requires the heavy lifting equipment.
I didn't take any pictures on taking it out, but it was fairly simple, but it is a 2-person job. It also requires some heavy lifting help; I used my skid loader with forks and a pallet set at the same height as the generator and slid it on after it was all loose. Basically, the power cables, positive and ground need to be removed, I took the positive cables, 2 of them off at the batteries first for safety. Then the fuel lines, also 2 of them, make sure to label what goes where. After that there are 4 bolts holding it down you need to impact out, all 4 of mine snapped off because the generator frame is aluminum, and the bolts are steel and after time they don't like each other. I'm having the shop get the broken pieces out. Then we just slid it out a few inches to get at the back side where the wires are. 2 set of wires, 1 with a weather pack plug, just unplug, and another in a flexible Romex cable that goes into the switch box under the bed. 5 wires in it need to be disconnected and be sure to label them. After that we just slid it on the pallet and loaded it into my pickup, fairly easy but it requires the heavy lifting equipment.
Thanks for the update! Make sure the shop replaces the coolant thermostat while it's out. Can't replace it w/o removing the gen which means mine will not get replaced until I get indications that the thermostat is going bad.
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Dave & Patricia
2017 Seneca 37FS
2016 Toyota Highlander
Kar Kaddy SS
I don't know about the code but if you changed the fuel filter and should have, look on the engine were the fuel line or lines go into the injector don't if it is a single or dual cylinder, but either way, the fuel pump pumps fuel to the injector pump, then the pressure is built up and line or lines go to the injectors, loosen the about a 1/2 round or so, turn the start button, if it is air locked you will see bubbles then the fuel will come out and close the lineup do this on both or one line and it should start, what you described sounds like air lock.