05/06 R/T Onan Gen run problem

[Whiskyecho]

Hi folks - sold my Van a while back but the new owner called and said he's having trouble getting the Generator to run. Says it'll start and run for a very short time, then quit. Said he hadn't started it for a couple of months. I'm starting to think it might be a carb problem (gas sitting ?). Any opinions, suggestions, etc that I might be able to pass along to him ? (I suggested that he sign-up to the various forums, do searches and post the problem - so he might be here in a bit). Let me know what you think. Thanks.. Bill

[markopolo]

Yup, probably some gunk in the carb.

Tell him to make sure the RT has more than half a tank of gas. I'd start the RT then start the gen & see if it will run longer when the van motor is also running. He could also tray to spray some carb cleaner into the carb.

My Onan 4000 has a solenoid attached to the bottom of the carb bowl. It is fairly easy to take off clean the gunk off.

I didn't have a generator on my Roadtrek so I never had the pleasure of working on one.

If he gets it going then run it for an hour our more.

[Ron J. Moore]

Might tell them to pick up a can of SeaFoam Gas Treatment and put the whole can into the gas tank; it will clean out that carb varnish that has built up and get it up to peak. He can pick it up in WalMart ($6.8. Also, if he is so inclined to tackle spraying down the carb, I'd recommend a product called Deep Creep (Same as S/F but in spray version). I have used these for years and they really do the trick. This ethenol gas is playing havoc with folks also, so the StaBil (Blue type) is being sold pretty quickly.

[Whiskyecho]

thanks to both of you for the replies - I've sent both to the fellow

Marco your suggestion about the Van's gas tank jogged my memory - I remember reading that R/T - Onan has a safety thing built in where the Gen can only use the Van's gas down to a certain level (1/4 tank remaining ?) and then it'll shut down - so that it can't fully deplete the tank.

I suggested, via email, that the fellow check the Van's gas quantity and make sure the Van is parked somewhat level - so as to not expose that "certain level"

I also told him that I used to start the Van, then the Generator, then load it up with the a/c AT LEAST ONCE A WEEK and run it for 15-20 minutes - I believe the Owners Manuel suggests that it be "exercised" frequently..

Thanks guys. Bill

[g1g]

I'm guilty on not excrecising and whenever I start it up I run into the same thing. In fact it happened today. I found if I put fresh gas and just letting it run will do the trick. I also have put gumout in the gas tank to help clean everything. I take it that the seafoam product is similer. When doing that I think it cleans the carb faster. After running it for a hour or two it seems to be fine.

[Mike]

For a newbie RVer it may well be the fuel level is too low in the gas tank.
You were right about the 1/4 tank cut off level in Roadtreks.
After that, possiblly gunk in the carb, try carb cleanout, as suggested here,
and once started, may need a good long run time for exercise, at least an hour.
So far, I've found with my '02 2800 Microlite, it does seem to start better
and keep running when the batteries are enabled first, and the van's engine
is also already running, before hitting the start generator switch.
They also apparently have a low oil level shut off, so that might be worth a look.
I was having problems with mine a while back, and after poking around the van's many parts,
I discovered a loose/corroded battery connection from the generator to the coach battery.
Once that was fixed, the starting was much better. (I think markopolo originally suggested
checking the battery connections during my diagnostics. )
I also note when starting my gen, the coach lights dim (they run off the coach batteries),
and my battery gauge indicator needle also waggles below charged when the start button is
pressed, so it seems to be drawing from the coach AND chassis batteries when starting.
(At least on mine it does, but I still have a flaky battery isolator, until next month, I hope!)
So check those battery connections. Could be a part of the problem.
If all else fails, google Onan repair facilities and suggest they take it in.

[Joe]

As you can see from some of my posts. I have had my share of problems with my Onan Gen. In reference to the gas line to the vehicles fuel tank beeing set for 1/4 tank shut off. It is suppose to be just that but one of the problems with mine was the copper tube to the tank was not bent correctly. My gen. would run out of gas at better that a 1/2 tank. I had to pull the line and adjust to 1/4 tank. I have tried carb cleaners and pulled the unit out and cleaned the carb. However, I still have not got the thing to run correctly. Sometimes it will run great and others it will run for a while and quit. I have been working on it on and off for two years. I usually start the vehicle first, start gen. and let run for a few min. I then turn on the breaker and add a load. This seems to work best for starting. I am going to take it in to the Cummings repair and let them look at it. When I find out what was wrong will post same. Maybe save someone else some time and trouble.

[Mike]

There's nothing more frustrating than a problem that won't go away,
even when you've tried everything you, and everyone else, suggests as a
possible cause.
Like I said, sometimes the only way to find out why something isn't working quite right,
is to bite the bullet and get a qualified service center to take a look at it.
I've looked around up here in Ontario, and there's a couple not too far from me.
I'll be taking mine in sometime in the next month to get an oil change and a
once over, just to see what else they think my Onan might need.

Regarding Onan generators and their problems, it has been mentioned on here that
the fuel lines aren't always perfectly bent, or lowered far enough into the main gas tank to
to get to the fuel to run when the tank is more than 1/4 full. So, it isn't surprising that yours
wasn't quite right. It has happened before.

I recently changed an old, tired, and apparently leaky lead acid wet deep cycle battery,
for a newer AGM version, and my Onan 2800ML seems to start better, ever since.
The Onan is only supposed to draw from the house batteries (I have 2, one wet, and
one AGM now) to start, and I think it's getting more cranking power from the new AGM
I added to the coach battery mix.

It might be worth looking into the quality and age of your house battery(ies?), if you suspect it/they
are getting too tired to start the generator, replacing it/them might help.
When you do find out what else was wrong, do post it up.
We can all benefit from our experiences.

[shezonit]

My '96 Class B has an Onan Microlite 2800 with 28 hours on the meter.... ( yeah.)
It started first try in the summer. I was gone awhile and now in the cold, I doesn't start. I run the van engine a few mins 1st. I look at test panel,shows house battery green light ( altho I know the house batt is dried out and doesn't hold a charge). Genset will NOT start.... oil ok and clean, van gas tank full. I read troubleshooting in manual. Any ideas? I am headed south soon. Maybe it'll start in warm weather (like me) :>)

[Ron J. Moore]

Shezonit, change out that battery.....it will be the source of many future problems. You mention you haven't started in a while, but put in fresh gas. Pick up a couple cans of SeaFoam and drop them in the tank and drive it so as to get it mixed good in the tank and lines. With a new batter, the SeaFoam, you should be able to start it, it will run rough for awhile, but it will smooth out. You need to try and exercise it regularly, it is one of the best devices you carry. Safe travels and enjoy heading South.

[Mike]

Did you try starting it while the van's engine is running? Does it turn over but won't catch?
I usually get a higher reading (green) on my battery charge panel when the van's engine is
running, because it's charging (or trying to) the house battery. Replace the dry/dead battery
with a charged new one, as Ron suggests.
If you look at your house battery there are probably 2 (or more) wires connected to the positive post.
One will be the one that feeds the house appliances and outlets, one is from the isolator/charger,
(they may be the same wire on some configurations)
and another probably goes to/from the generator. Make sure they're all good clean connections, and the
wires are not broken or damaged inside the insulation somewhere.
markopolo suggested this to me last year, and it turned out to be the reason my generator wouldn't start.
The connector/wire from the generator was corroded inside the plastic insulation wire cover.
I cut the bad wire/connector off of the wire, and replaced the connector, and it started.

[Joe]

My 95 only had 80 hours run time when I bought it so it was not used much either. As for the not starting in cold weather. Mine has a small plastic cover you are suppose to snap on over the air cleaner during cold weather. Might try that.

[shezonit]

Yes, I have van engine running.... test panel shows battery green then.
I am going to get a new battery in AZ. I figure there are a lot more RVs down there, should be more choices. I'll give up on the generator until I get there.
As I said, it ran fine in warm weather.... both in AZ and Montana.

[Mike]

Nope, I'm stumped. If it won't start and you're near a CumminsOnan repair shop that does
RVs maybe have them take a look at it. Might be worth an hour of diagnosis time to find
out what the problem is. Here's their website with a store locator but be warned, there
aren't very many. They do have a downloadable POI file for your GPS toys, though.
http://www.cumminsonan.com/
I think Camping World is an authorized repair facility, as are probably other RV shops.
Onan generators are pretty finicky it seems, but they are really nice to have when they're working.
I think most everyone who has one, has had it refuse to cooperate at least once.
Let us know if it starts, or if you find out what it was.

[Joe]

You said it started fine in warm weather but not in cold. As I said in my last post, mine has a plastic cover that now I remember is called a preheater that snaps on over the air cleaner for cold weather starts. I added some carb cleaner to the gas and started it with the vehicle motor running. The gen ran for over 2 hours without any problem. Hope my problem is solved but still do not trust it. I could not find the same carb cleaner as was recomended but bought the best stuff I could find. Maybe that brand is not available in Maryland. Good luck!!!

[Mike]

Originally Posted by Mike

There's nothing more frustrating than a problem that won't go away,
even when you've tried everything you, and everyone else, suggests as a
possible cause.
Like I said, sometimes the only way to find out why something isn't working quite right,
is to bite the bullet and get a qualified service center to take a look at it.
I've looked around up here in Ontario, and there's a couple not too far from me.
I'll be taking mine in sometime in the next month to get an oil change and a
once over, just to see what else they think my Onan might need.

Sorry to wake up an old thread(again?), but I've got more/new problems with my genset.
Took my van in to a qualified Roadtrek servicer, and asked if they'd be able to do the
isolator (finally) replacement, and an oil change on my genset. They said no problem.
The place is about 42 kms away from me in so I made the appointment
for yesterday.
I brought them the van yesterday morning, they finally got around to it around 11:00 and it was
done by around 13:00. Problem was, now the genset won't turn over. They asked me if I wanted them
to try to figure it out, and I said, "uh, duh, yes!".
Well about an hour later, they still had no idea. I asked if they checked the breakers, they said the unit
is getting power (no idea how they determined this), but neither the remote or casing start switches
do anything. It's dead now. (charged me an hour labour to NOT figure it out).
I had the bed made up as a king, and they didn't go near the charger panel. I will check it today.
I pulled up the owner's manual electrical schematics and there appears to be a 50 amp breaker on the genset,
somewhere. I have no idea where it is, if anyone knows, and can give me a clue?
I'm going to check all the coach battery connections, on both of them, and the breakers inside the charger
panel. I think the new isolator is OK, and the wiring looks like it did on the old one, so I think it's OK.
It's full of oil (according to them), so I don't think it's a low oil condition.
Any other things I should check before I take it to the Onan guys, and spend more on it?

I also sent Roadtrek Service a note describing the situation, and am waiting for them to reply.

Geeeeeeez, Louise!!!!

[Joe]

I will check my books and look at the gen. itself. I do not recall seeing a breaker other than the one on the side of the gen. you are suppose to switch off if you start gen. from outside. Mine is hard to get started but now, or should I say for now, runs smoth and has not cut off. Knock on wood! If I come up with anything I will write back. *

[Mike]

Hey, thanks Joe.
Well, I've checked the breaker panel and there doesn't appear to be any fuse or breaker labelled
"Genset". So that's out. I'll see if I can get down underneath it and check the casing for any other
"breaker" looking things, but I really am not familiar (obvious) with these things.
The batteries all look connected properly, and the isolator connections appear to be identical to
the way they were on the old isolator (which had a bad diode, they told me).
Another problem has noe reared, or re-reared it's head. I left the "battery enable" switch on the
monitor panel enabled Wednesday night, and low and behold, the vehicle wouldn't start Thursday
morning. This was the problem which started this whole isolator replacement problem last year.
The only real difference with the new isolator install, is they sprayed some sort of sticky red stuff
all over the face of the isolator, I would assume to protect the connections. I have no idea what
brand or type, but I'm wondering if it's electrically conductive, could it be shorting the terminals
on the isolator? Could that explain the recurrence of the dead car battery situation and possibly
affect the genset getting current to start? I'll add some pics of the old and new isolator to the thread
in case anyone sees anything obvious.

[markopolo]

That's frustrating.

Here's a Onan generator troubleshooting pdf file that has helped others solve generator problems:

http://www.flightsystems.com/pdf/onanrvtshootgd608.pdf

So you still have the original problem plus a non-starting generator.

Mike - I'm sure you've checked things like making sure your inverter is off etc. re: the dead battery.

Did the gen starter at least make a clicking noise when trying to start it?

[markopolo]

I looked at a 2800 series operator manual and it shows a 5 amp DC fuse that you could check to make sure it is not blown.