Generator will not start

Our generator just stopped working while we were driving in hills on our last trip to Roman Nose State Park in Oklahoma. We have taken it to one place and they said the the magneto on the generater has gone out. That seems strange since it is a 2011 model and it does not have that many hours on the generator. Where is the diagram of the location of the generator on the Phoenix?  I cannot find it on the internet.
I would appreciate if you could direct me to this schmatic.
If anyone has any ideas as to what the problem might be, please post. Thanks.

Take a look for some trouble shooting on the web. IF it is the magneto it’s prob about a $100 part. The issue is it’s labor intensive so I’d expect it costing at least a grand to have it fixed.  The gen will need to be removed from the PC for the magneto to be changed out. If your mech inclined you could do it yourself.  A transmission jack would probably work pretty well to lower it and they can be rented .

I’d have a second shop test it first before committing to doing it yourself or having it done.

Where is the diagram of the location of the generator on the Phoenix?  I cannot find it on the internet.
I would appreciate if you could direct me to this schmatic.
If anyone has any ideas as to what the problem might be, please post. Thanks.

The generator is located on the driver's side at the front of the wide part of the RV.   If you have a slide out, the door to the generator is under the slide out.

If it was running and just quit, it could have run out of gas (if your Phoenix gas tank is below a quarter of a tank) or the fuel pump may have failed.    The best place to have them serviced is at a Cummings repair shop.  Cummings owns Onan.

I’m guessing if a shop said it’s the magneto they had to have eliminated fuel issues. However you never know shop to shop which is why I suggested having another shop take a look.

Joseph and donc13 are offering good advise.  Misdiagnosis happens all the time with everything in life.  If you can, take the rig to another repair center and see what they determine.

The Onan generator not starting is a common problem discussed on other RV forums.  I never read any posts referencing the magneto.  That is the only reason why I would question the diagnosis.

The obvious question is: How much gas was in your fuel tank at the time the generator stopped?  Maybe when driving in the hills, the fuel sloshed to one side, preventing the fuel from being sucked-up.  The fuel cut-off is supposed to be 1/4 full, but on a slope, it could change.  On our PC, the fuel cut-off is a bit above 1/4 full, and I don't know if it is affected when on a slope.

The Onan's fuel pump would be the next thing to check which anyone can do.  With everything very quiet, prime the generator by holding the start button in the opposite direction.  You should hear a humm or buzz.  If you don't hear anything, get someone with good hearing to crawl under the generator and listen while you prime.  There is duplicate start-with-prime button on the generator itself so you can check to see if the fuel pump is working by yourself.

One more thing to check.  There is a circuit breaker next to the start button on the generator itself.  Check that too.  Make sure it has not tripped on you.  I don't recall if tripped that it prevents the generator from starting, or it runs but won't generate electricity.

Did I read that right?  Is running the generator while driving a common thing to do?   I can't think of a reason I'd do that, and we don't even have a built in inverter.

I'd be amazed if it was a magneto.  But it's easy to test.  If the engine coughs even once when you prime and crank, it's not the mag.  If you can't get a cough, remove a spark plug and lay it on the engine block (but don't hold it with your hand, unless you want a big surprise!).  Then watch it while you crank  If you see a spark, it's not the mag.

Before I paid a guy $1000 for a new mag, I'd make him prove it was bad.

Did I read that right?  Is running the generator while driving a common thing to do?   I can't think of a reason I'd do that, and we don't even have a built in inverter.

I'd be amazed if it was a magneto.  But it's easy to test.  If the engine coughs even once when you prime and crank, it's not the mag.  If you can't get a cough, remove a spark plug and lay it on the engine block (but don't hold it with your hand, unless you want a big surprise!).  Then watch it while you crank  If you see a spark, it's not the mag.

Before I paid a guy $1000 for a new mag, I'd make him prove it was bad.

Jon,

Yup on driving with generator running. Our first motorhome was a 2000 Winnebago Mini that we bought brand new.  The dash a/c did about nothing to cool off anything but the driver and passenger.  The dealer told us to run the generator to run the coach a/c while driving.

That made my 2 kids quite happy!    Even after the kids no longer traveled with us, we did that when it was hot out so when we stopped, the living area was cool.   Only issue we had was the generator failed just as we were headed into Florida during a heat wave.  Temps and humidity in the upper 90's.   We headed North and then back home!

We still occasionally do that in our PC to cool off the back end an hour or so before we stop for the day to help start cooling off.

It "cost" about 1 mpg on fuel but was worth it.

Don

Blue, I agree on testing and I’m assuming the shop did that before making  that evaluation. I did a little search and the Magnetos going bad with the Onan are not as rare as I’d thought.

As far as running the gen while traveling any large rig is always running the gen while driving in the summer. It’s the only way to keep it remotely livable inside on hot days.

The op hasn’t posted again so I guess they figured it out or moved on.

Blue, I agree on testing and I’m assuming the shop did that before making  that evaluation. I did a little search and the Magnetos going bad with the Onan are not as rare as I’d thought.

As far as running the gen while traveling any large rig is always running the gen while driving in the summer. It’s the only way to keep it remotely livable inside on hot days.

The op hasn’t posted again so I guess they figured it out or moved on.

No kidding! Never thought of that. Well, this is my first RV, and the chassis A/C seems to work well enough for my little 2350 that it wouldn't have occurred to me (especially after I installed that cutoff valve in the fuel line, after the Onan carb fiasco).  Odd that there's not a better solution, though.  City buses have an A/C on top but I don't think they use a generator.  The engine generator must be large enough to handle the load.  I wonder why RV's aren't designed that way,

Quote from: Joseph on July 02, 2020, 10:07:55 am

Blue, I agree on testing and I’m assuming the shop did that before making  that evaluation. I did a little search and the Magnetos going bad with the Onan are not as rare as I’d thought.

As far as running the gen while traveling any large rig is always running the gen while driving in the summer. It’s the only way to keep it remotely livable inside on hot days.

The op hasn’t posted again so I guess they figured it out or moved on.

No kidding! Never thought of that. Well, this is my first RV, and the chassis A/C seems to work well enough for my little 2350 that it wouldn't have occurred to me (especially after I installed that cutoff valve in the fuel line, after the Onan carb fiasco).  Odd that there's not a better solution, though.  City buses have an A/C on top but I don't think they use a generator.  The engine generator must be large enough to handle the load.  I wonder why RV's aren't designed that way,

Bus a/c works just like auto a/c, just much larger compressors.  Belt driven via the engine.

Well, this is my first RV, and the chassis A/C seems to work well enough for my little 2350.....

The same here.

When driving our 2350 with thermal windows and no slide out, it is comfortably cool on our rear corner bed.  I don't know how much gas is consumed idling the V10 engine versus running the generator, but the a/c from the dash board is quiet, and seems to offer colder air.  Maybe it's because so much heat naturally originates from the cab area.  Having the a/c air originating from the same area, maybe it cancels out that heat.

Huge difference between a 40’ DP with 7 + foot ceilings going down the road and a 2350 PC. Not having or having a slide would make absolutely no difference in ac needs while moving.  Even my 28 foot stays comfortable driving with just the fords ac. All that aside sitting at a camp ground it’s not enough nor can I imagine running a V10 at idle just to attempt to cool part of a parked RV.  I wish our 2552 was a 50 amp with 2 Houghton ac units.

I’ve seen 40+ foot diesel pushers with Oman diesel generators with thousands of hours on them.  A huge 40 footer wouldn’t be for us but for many as well as full timers it’s the ticket and knowing you can run a diesel gen thousand of hours to keep cool is a big plus. not having or having a slide would make absolutely no difference in ac needs while moving.

Quote from: BlueBlaze on July 02, 2020, 08:01:51 pm

Well, this is my first RV, and the chassis A/C seems to work well enough for my little 2350.....

The same here.

When driving our 2350 with thermal windows and no slide out, it is comfortably cool on our rear corner bed.  I don't know how much gas is consumed idling the V10 engine versus running the generator, but the a/c from the dash board is quiet, and seems to offer colder air.  Maybe it's because so much heat naturally originates from the cab area.  Having the a/c air originating from the same area, maybe it cancels out that heat.

Ditto.  Even in Florida heat, I can put the center vents pointing straight back, left side vent on me and the whole rig stays cool going down the road. . And thats with single pane widows, slide and stainless wheel covers. 

Bill,  even with stainless wheel covers?  Now your stretching it.

We’re heading out next week with temps forecast to be in the 112-116 degree range.  Not bad today at 106 and it was 82 when I took the pooch to the park at 5 am this morning.  This is when I wish I had 2 ac units and 50 amp.

Want to become a billionaire.... develop an insulation that’s thin , maybe a 1/2 thick pliable blanket with say an R rating of 40 that’s not a gazillion dollars a square foot.  Hmmmm wonder if there’s any shuttle panels laying around