Hi guys, I recently purchased an Rv for my race operation. When I brought it home everything worked fine but after I plugged the Rv into 110 shore power and tried to run one of the AC units without success it now, when I unplug from 110 and start the generator, runs but isn’t putting out any power from the generator. I have checked the breakers on the generator and all the fuses I could find but I don’t see any issues. We suspect it may be the voltage regulator but because of the cost to replace it I would like to be able to test it somehow first to be sure it’s the problem or not. I hear there is an Onan generator expert on here so I’m hoping he or someone else may know how to test it or have any other ideas of what the problem may be. Thanks in advance for any advice

I'm sure Rich will be along at any time now BUT just for the sake of argument did you check all your 110 volt circuit breakers.
They look just like household breakers and are usually in a small metal box (similar to your house).
Mine was under the bed.
Friends was in overhead compartment above drivers seat.
When this happened to me I just reset them all.
FIXED.

A Marquis 7000 is the name they used on the OLD design Onan

Is it an all metal Black machine ? An old Motorhome ? The Marquis 7000 stopped being made about 20 years ago if it is....

They did use that name again on some of the newer design machines as well....

Most Onan's will not stay running if they are not producing AC output voltage....

You need to start at the source.....the generator. The breaker either 1 or 2 onthe machine itself.....Does it have power in and out ? Does it have a connection box near the machine/ Is power there ? Down the line to either an ATS or a manual connection box....

Sounds like an ATS....Automatic Transfer Switch...They fail regularly and could easily be your problem.....

Every Onan has a label with the Model info on it

If you tell me the letter code on the label I can tell what machine you have...

The old machines were NHE or NHM than some numbers and one letter. The year it was built is in the serial number below the Model info line...

This message has been edited. Last edited by: SCDIV1,

x2 on transfer switch

I did one last week and man that one was a B-i-t-c-h

Had to add a separate splice box since the coaches existing feed wire was way over size and to stiff to get into the new ATS

Spliced in a nice SJ cord and that took hours !

Last year I did one in a Toy Hauler and the ATS was inside the cabinets behind some drawer fronts

I try not to go beyond the generators but give in sometimes and usually pay the price...

I get beat up bad working in those tight spaces....

Just did a '98 BGE pullout and fix the NO spark from rodents.....and back in with a new exhaust....an old P.O.S. MH but "I don't judge" HAHAH LOL..Owner is quite a piece of work too...

The generator is in a 2000 Forest River Reflection so it may be the old style. I had a couple friends over who checked the power for me since I’m not great with electrical stuff and they said there was no power to the output cable on the generator. The auto transfer switch is in the rear of the coach but when the checked it we could get power on the 110 side when plugged in but nothing on the generator side with it running and 110 unplugged. I am actually out of town and away from the Rv this week but when I get back I can get u the model and letter codes u were asking about

It's most likely the older type Onan, all metal black sheet metal covers

1 or 2 breakers on the side right behind the front panel that has the start/stop switch on it.

I would remove the 2 torq screws that hold the front panel in place to get at the breakers

It's a birds nest of wires in there and the battery cable will probably need to be pulled off to get the panel out

Reattach the battery cable and run the machine

Use a volt meter and check the voltage at the breakers....one side is the AC power direct from the generators windings and the other side is AC power out with the breakers on

You can probe one side to anything metal and the other side to the breaker terminal

If your not comfortable with live voltage get someone who is.....You can get shocked !

If there is no voltage at the side from the windings to the breakers......the generator needs to be looked at by someone

Roger that, thank you Sir. I will check that out when I get back home

Update…I pulled the front panel off and ran the generator. I have 124v across the top breaker but nothing across the bottom breaker. So does that mean the bottom breaker is bad?

Check for a a hidden breaker on or around the generator itself. The one on my old motorhome had a hidden breaker that you could feel but not see. It would occasionally trip when driving with the genny on.

Both breakers are fed 120 volts from some terminal strips at the back of that compartment

Each breaker has a black wire from back there to the input side of the breaker

You would be using a voltmeter to that input side of the breakers, one at a time and the other probe from the meter to any good metal surface in there

If you don't have 120 volts IN to one breaker, trace the black wire back to the terminal strip.

It's either loose or disconnected....

I don't think those machines were 120/240 output.....120 only so if one breaker is fed 120 from the terminal strip, the other one should be also getting the same 120 volt feed.

The terminal strip is direct from the windings of the generator and there is nothing else other than a broken or disconnected wire or possibly the breaker is bad

If you have 120 volts into the breaker, with it ON, you should have 120 volts on the output side....TO GROUND or neutral....white wires are neutral and everything on an Onan is common with any ground or metal surface of the engine, machine, battery....

The breaker itself can easily be tested with an ohmeter......out of the circuit....Off...open one side to the other....ON closed one side to the other

I'm feeling like a shop teacher.....electricity and testing....101 !! LOL

Yeah but you’re a great instructor!
Keep teaching!
I scored! Jeff Jackson S/ST gave me a complete low ours 7000, rotor fail but motor is solid! Now to get it here!

Given my very limited electrical knowledge I truly appreciate the shop class lessons lol. On a serious note I am learning a lot and I appreciate ur info. So I checked as u said and I do in fact have 120 on the input side and 120 to the output side when the breakers are on. So maybe it’s not a generator issue at all then? I’m currently trying to trace the wires to see where it goes from there so I can chase the power to wherever it stops to find the issue but like u said before it’s a cluster of wires in there and it’s hard to see where they go after the output side of the breaker

If you have output from the breakers that’s good.
We’re making progress. The wires usually go into a metal or plastic shielding and maybe to a box near the generator. Sometimes yes and sometimes no box. It is a convenient place to disconnect the generators output wires when the machine needs to be pulled out. Old MH’s don’t always have that box. The output is usually fed to the compartment where the shore cord is. If it has an automatic transfer switch it might be there. Some MH’s have no ATS. They have a box where you plug the shore cord into and that box has generator feed wires in it. No ATS to go bad with that type setup. If it does have an ATS as I think we touched on that can easily be your problem. Gotta find what it has and continue testing. It’s easy for me but I have a lifetime of experience. I was an electrician not long after high school so it’s very easy for me.

I now have power to the transfer switch but nothing coming out of the transfer switch when running the generator. I was reading the cover panel for the transfer switch and saw an area that said there was a led that should be lit when properly functioning but it wasn’t on. Beside that led was a switch and according to the cover its a delay or bypass for the time delay control module. I flipped it to bypass and the led lit up when I turned on the generator and now I have power again. My question is should it be on delay to function properly or did it somehow get switched and should actually be in the bypass mode. I’m happy to have power back in the Rv from the generator but I don’t want to bypass something that shouldn’t be bypassed

The delay feature is just so there is a little time before the generator sees a load like the AC hitting it as soon as the generator is online...

It's a good feature but all you need to do is turn things off before shutting off or starting the generator....and that really should be done anyway...

A little off the subject but once I got rid of those stupid Ground fault outlets on my trailer 99% of my electrical problems were fixed.

I know they are supposed to be there for your safety, but you couldn't drive down the road without those damn things tripping and then when I got to the track I had to hunt down which one tripped. I left the one by the sink in the living quarters but the rest of them are gone.

Thanks for all ur help, I appreciate it

Rich is a wealth of knowledge and always helps us out like to let him know he is greatly appreciated here