Generator will not turn off once started

Tiki guy · 07-26-2022, 05:25 PM

Hi all I need some help. I have a 2022 Thor Four winds 28z. In April I was testing the generator and started it for 30 minutes and it would not shut off at the panel or the switch at the generator. The only way I could turn it off was pull the spark plug wire. I call Cummins and took it in for repair. They ran it over an hour and it shut off. They did this twice. So they said nothing was wrong.

I just fired it up yesterday and ran it for over 30 minutes and went to shut it off and it would not shut off again at the panel or at the generator switch. I had to pull the spark plug again to shut it off.

While this might work and a emergency back up I would like to figure out why it won’t shut off.

Has anyone else had this problem ? Any ideas what’s wrong ?

Thank you for any help of suggestions

JimOIB · 07-26-2022, 09:39 PM

On my coach I need to hold the genset switch in the STOP position for 7-8 seconds for the genset to shut down. Manual says to turn off a/c and major appliances, let the genset run 2 minutes to cool down then press STOP. I usually count to 10 and can hear it wind down. It works for me.

javelin · 07-26-2022, 09:39 PM

I don’t know your coach or gen specifics at all, but I think the stop switch(es) apply a ground connection back to the generator control module (my name for it) located at the gen, which should drop out the run relay internally and release the fuel solenoid and stop ignition.....to turn things off. It sounds like you have an intermittent ground “stop” connection somewhere which sometimes works and sometimes does not. I would check around the gen control module to make sure all control wiring connections (like associated plugs or grounds) look clean and tight. I am not sure, but the “remote stop switch” ground may be provided by a wire from the gen control module itself. I assume the local gen stop switch would also tie into that remote switch "return wire" as a multiple and then connect into the gen control module. So if both switches can’t stop the gen on certain occasions, then the trouble might be an intermittent connection close to the gen control module itself? Purely a starting WAG.

The Gritz Carlton · 07-27-2022, 01:25 AM

Not familiar with the actual motor that runs the generator (mine is a Kubota) but is it possible it has a fuel supply solenoid that isn't" pulling back" to shut off fuel supply? With it being a gas motor it could be something in the possible solenoid that shuts off the power supply to the ignition...or a wire in that system that has worked loose. Most people have issues with them not starting...I don't think I've seen a post here with it not shutting off.

Tiki guy · 07-27-2022, 02:17 AM

Quote:

Originally Posted by The Gritz Carlton

Not familiar with the actual motor that runs the generator (mine is a Kubota) but is it possible it has a fuel supply solenoid that isn't" pulling back" to shut off fuel supply? With it being a gas motor it could be something in the possible solenoid that shuts off the power supply to the ignition...or a wire in that system that has worked loose. Most people have issues with them not starting...I don't think I've seen a post here with it not shutting off.

Thank you

Jimbo56 · 07-27-2022, 11:14 AM

I wonder what was different at your place than at the Onan place. Temp? Humidity? Are you holding the stop buttons down until it slows to a stop? I can’t imagine why it would stop for Onan and not for you. We’re you level? This is a head scratcher!

dkoldman · 07-27-2022, 01:01 PM

Quote:

Originally Posted by Jimbo56

I wonder what was different at your place than at the Onan place. Temp? Humidity? Are you holding the stop buttons down until it slows to a stop? I can’t imagine why it would stop for Onan and not for you. We’re you level? This is a head scratcher!

OP is savvy enough to know how to pull the spark plug wire so it suggest he knows what he is doing.

I don't understand why Onan run 1 hour and OP 30 minutes if they are just checking it to cut off? Isn't minimum run time 10 min?

Does OP have a AGS? If so does it stop at quiet time?

When at Onan, was OP there when they turned it off to see if he was doing anything different than they?

I could easily cite faulty wiring from switch inside the RV, but if button outside does not turn it off I get skeptical. I think the Gritz is on to something, but seems like Onan would have said more than it works, unless it really does work

**16ACE27** · 07-27-2022, 02:40 PM

Quote:

Originally Posted by Tiki guy

Hi all I need some help. I have a 2022 Thor Four winds 28z. In April I was testing the generator and started it for 30 minutes and it would not shut off at the panel or the switch at the generator. The only way I could turn it off was pull the spark plug wire. I call Cummins and took it in for repair. They ran it over an hour and it shut off. They did this twice. So they said nothing was wrong.

I just fired it up yesterday and ran it for over 30 minutes and went to shut it off and it would not shut off again at the panel or at the generator switch. I had to pull the spark plug again to shut it off.

While this might work and a emergency back up I would like to figure out why it won’t shut off.

Has anyone else had this problem ? Any ideas what’s wrong ?

Thank you for any help of suggestions

The generator, just like a lawn mower engine, stops by applying a ground to the ignition coil.

If it wouldn't stop JUST from a remote switch we could assume a poor ground connection in/to the remote wiring harness.

Not stopping from the local control switch indicates the ground is not being applied to the coil so I would look at the wiring connection at the coil - it may be corroded/intermittent.

Jimbo56 · 07-28-2022, 10:51 AM

Quote:

Originally Posted by 16ACE27

The generator, just like a lawn mower engine, stops by applying a ground to the ignition coil.

If it wouldn't stop JUST from a remote switch we could assume a poor ground connection in/to the remote wiring harness.

Not stopping from the local control switch indicates the ground is not being applied to the coil so I would look at the wiring connection at the coil - it may be corroded/intermittent.

But he said it worked perfectly at Onan shop.

Bob Nodine · 07-28-2022, 11:22 AM

Quote:

Originally Posted by Tiki guy

Hi all I need some help. I have a 2022 Thor Four winds 28z. In April I was testing the generator and started it for 30 minutes and it would not shut off at the panel or the switch at the generator. The only way I could turn it off was pull the spark plug wire. I call Cummins and took it in for repair. They ran it over an hour and it shut off. They did this twice. So they said nothing was wrong.

I just fired it up yesterday and ran it for over 30 minutes and went to shut it off and it would not shut off again at the panel or at the generator switch. I had to pull the spark plug again to shut it off.

While this might work and a emergency back up I would like to figure out why it won’t shut off.

Has anyone else had this problem ? Any ideas what’s wrong ?

Thank you for any help of suggestions

You do not indicate if when you pushed the stop switch if the generator stopped and then started again after you released the switch. On a previous motorhome we owned that had AGS, if the generator was being commanded to turn on because the internal temperature of the coach was high it would persist on running until the temp was down or the time had expired and would start back up when the stop switch was released. In those days the coach was outside before we built the garage and plugged into a 50 amp outlet on the side of the house. When cutting the grass we would disconnect the shore power cable and if the AGS was enabled the generator would start on high temp in the coach. I would have to disable the AGS to get the generator to stop.

**16ACE27** · 07-28-2022, 01:15 PM

Quote:

Originally Posted by Jimbo56

But he said it worked perfectly at Onan shop.

Did you see the word "intermittent"?

JimOIB · 07-28-2022, 07:08 PM

ACE is right, it’s just like a lawn mower. And with a lawn mower a simple move to the STOP position takes a few seconds for the engine to wind down and stop. The STOP button on the genset needs to be held down for 6-7 seconds or the genset will continue to run. That’s how my coach works.

Onan/Cummings knows that…does the OP?

**16ACE27** · 07-28-2022, 11:09 PM

Quote:

Originally Posted by JimOIB

ACE is right, it’s just like a lawn mower. And with a lawn mower a simple move to the STOP position takes a few seconds for the engine to wind down and stop. The STOP button on the genset needs to be held down for 6-7 seconds or the genset will continue to run. That’s how my coach works.

Onan/Cummings knows that…does the OP?

Actually....... the 4K generator just requires a push to the stop position to shut down - no need to hold it in the STOP position.

javelin · 07-28-2022, 11:09 PM

I hate to be a party pooper, but on my ACE, when I operate the stop switch on my 4KW Microquiet gen, it starts the shutdown immediately and I do not have to hold the button in stop position for more than a second to initiate the process. The gen runs down and stops in about 5 seconds or so. I do not have AGS, if that is making a difference to some.

JimOIB · 07-29-2022, 01:30 AM

Quote:

Originally Posted by 16ACE27

Actually....... the 4K generator just requires a push to the stop position to shut down - no need to hold it in the STOP position.

That’s not how mine has operated from day 1 - I need to press and hold the stop switch to get the genset to stop. Onan RV QG 4000 installed in a Class C. Maybe there has been an issue from the beginning.

Jimbo56 · 07-29-2022, 01:53 AM

Quote:

Originally Posted by 16ACE27

Did you see the word "intermittent"?

Yes I did. And no it doesn’t help! He can’t get it to stop. But the Onan people did get it to stop. Did you read that! Cmon Ace.

**16ACE27** · 07-29-2022, 02:28 AM

Quote:

Originally Posted by Jimbo56

Yes I did. And no it doesn’t help! He can’t get it to stop. But the Onan people did get it to stop. Did you read that! Cmon Ace.

C'mon, what? Intermittent means sometimes it works, sometimes it doesn't. It worked for the Onan people after driving it to them. It didn't work for the OP after returning home. Did you expect Onan to continue troubleshooting an issue they could not see/verify? If he has a corroded, intermittent connection on the coil's grounding wire this is exactly what could happen. Sometimes it makes connection, sometimes it doesn't.

JimOIB · 08-01-2022, 04:00 PM

Quote:

Originally Posted by JimOIB

That’s not how mine has operated from day 1 - I need to press and hold the stop switch to get the genset to stop. Onan RV QG 4000 installed in a Class C. Maybe there has been an issue from the beginning.

I found a diagram of the stop circuit and the genset should indeed stop with a press of the button. I went back over to my rig this morning and I definitely had to hold the stop switch down for 5-6 seconds to get the genset to stop. After probing around checking switches and ground I found the plug to the control board not fully seated. After disconnecting, cleaning the plug and socket with compressed air and seating it properly the genset stops with a single press of the stop button. All along I thought my genset was working properly only to find in this thread that it wasn’t. You learn something every day.

You may also like: