Onan QD 10000

C and W Racing · 02-17-2019, 11:36 AM

Where is the voltage regulator located on this generator? I’m assuming that is the problem because it’s putting out 174-180 volts on each leg
Thanks, Chuck

Rich Biebel · 02-17-2019, 12:07 PM

1 control board on those and it may have a small transformer that is part of the voltage control circuitry. The control board is located in a holder mounted on the barrel. To the left looking in the service door. A molded plastic area and the board is in a metal tray. 3 screws and one connector. That board does everything and it’s a $700 item. There are sensing wires on the output breaker and also the transformer I mentioned on some models. High voltage is not a common issue on those. I would be checking every wire connection. I have the luxury of having “test boards” to just plug in. I save old ones with other issues that I replaced. If you give me the exact model info of the ID label I can look up the machine and it’s wiring to see what’s in it. Model info is on labels in two places usually.

C and W Racing · 02-17-2019, 12:56 PM

Model is 10HDKCA11506C
S/N 1090029178

Any way you could send me a picture of it? After I posted the original question, I did check every wire and connections and now it shows 135 on one leg, 140 on the other. Automatic Transfer Switch was clicking on and off which is why I even started checking things. Now with the current voltage, the transfer Switch no longer switches with the generator at all

Rich Biebel · 02-17-2019, 01:14 PM

Open service door. Look to the left and on top of the generators barrel. Wire connector is right there. Big weatherpack connector. It plugs into the control. Has a lock you release to pull connector out. 3 10 mm screws hold the plates in that the board is bolted to. Nothing adjustable and nothing to service. You can release the connector lock and pull it up. Push it back in till the lock clicks and see if anything changes.

Rich Biebel · 02-17-2019, 01:34 PM

It should have shut down and lit a fault code. Secondary code should have been a 12.

Start the machine and open the circuit breaker on the machine itself. You need to read the voltage right at the input side of that breaker. It’s hard to get to but with proper clip on leads you can do that. Input side is bottom of breaker usually. A 2 pole breaker and if it’s a 240 output and I believe it is you should see 240 across both.

There is a sensing transformer and I’ve never found one bad. I don’t recall why they use that but the transformer is wired between the breaker and the control harness.

Erratic voltage output is going to be tough to diagnose without a known good control board. The wiring from the breaker to the control transformer and then to the control board connector has to be checked. That is usually not a problem though.

What year is the truck or coach ? 09 ? 00 ? How many hours on the generator ?

The control part number is 300-5961 from Cummins-Onan

C and W Racing · 02-17-2019, 02:17 PM

2010 Monaco 780 hrs
I had to stop looking at it because I had an appointment I needed to get to. Any chance of pm me your number so I could give you a call when I get back to it?
Thanks, Chuck

Rich Biebel · 02-17-2019, 03:47 PM

PM sent

02-17-2019, 11:36 AM	#1
C and W Racing Senior Member Join Date: Jul 2007 Posts: 557 Likes: 6 Liked 13 Times in 3 Posts	Onan QD 10000 Where is the voltage regulator located on this generator? I’m assuming that is the problem because it’s putting out 174-180 volts on each leg Thanks, Chuck

02-17-2019, 12:07 PM	#2
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,320 Likes: 25 Liked 557 Times in 217 Posts	Re: Onan QD 10000 1 control board on those and it may have a small transformer that is part of the voltage control circuitry. The control board is located in a holder mounted on the barrel. To the left looking in the service door. A molded plastic area and the board is in a metal tray. 3 screws and one connector. That board does everything and it’s a $700 item. There are sensing wires on the output breaker and also the transformer I mentioned on some models. High voltage is not a common issue on those. I would be checking every wire connection. I have the luxury of having “test boards” to just plug in. I save old ones with other issues that I replaced. If you give me the exact model info of the ID label I can look up the machine and it’s wiring to see what’s in it. Model info is on labels in two places usually. __________________ Rich Biebel S/C 1479 Stock 147R

02-17-2019, 12:56 PM	#3
C and W Racing Senior Member Join Date: Jul 2007 Posts: 557 Likes: 6 Liked 13 Times in 3 Posts	Re: Onan QD 10000 Model is 10HDKCA11506C S/N 1090029178 Any way you could send me a picture of it? After I posted the original question, I did check every wire and connections and now it shows 135 on one leg, 140 on the other. Automatic Transfer Switch was clicking on and off which is why I even started checking things. Now with the current voltage, the transfer Switch no longer switches with the generator at all

02-17-2019, 01:14 PM	#4
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,320 Likes: 25 Liked 557 Times in 217 Posts	Re: Onan QD 10000 Open service door. Look to the left and on top of the generators barrel. Wire connector is right there. Big weatherpack connector. It plugs into the control. Has a lock you release to pull connector out. 3 10 mm screws hold the plates in that the board is bolted to. Nothing adjustable and nothing to service. You can release the connector lock and pull it up. Push it back in till the lock clicks and see if anything changes. __________________ Rich Biebel S/C 1479 Stock 147R

02-17-2019, 01:34 PM	#5
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,320 Likes: 25 Liked 557 Times in 217 Posts	Re: Onan QD 10000 It should have shut down and lit a fault code. Secondary code should have been a 12. Start the machine and open the circuit breaker on the machine itself. You need to read the voltage right at the input side of that breaker. It’s hard to get to but with proper clip on leads you can do that. Input side is bottom of breaker usually. A 2 pole breaker and if it’s a 240 output and I believe it is you should see 240 across both. There is a sensing transformer and I’ve never found one bad. I don’t recall why they use that but the transformer is wired between the breaker and the control harness. Erratic voltage output is going to be tough to diagnose without a known good control board. The wiring from the breaker to the control transformer and then to the control board connector has to be checked. That is usually not a problem though. What year is the truck or coach ? 09 ? 00 ? How many hours on the generator ? The control part number is 300-5961 from Cummins-Onan __________________ Rich Biebel S/C 1479 Stock 147R Last edited by Rich Biebel; 02-17-2019 at 01:53 PM.

02-17-2019, 02:17 PM	#6
C and W Racing Senior Member Join Date: Jul 2007 Posts: 557 Likes: 6 Liked 13 Times in 3 Posts	Re: Onan QD 10000 2010 Monaco 780 hrs I had to stop looking at it because I had an appointment I needed to get to. Any chance of pm me your number so I could give you a call when I get back to it? Thanks, Chuck

02-17-2019, 03:47 PM	#7
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,320 Likes: 25 Liked 557 Times in 217 Posts	Re: Onan QD 10000 PM sent __________________ Rich Biebel S/C 1479 Stock 147R

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