Generator broken!

[Junodtim]

I believe they put too much oil in it. The manual says the oil level should be halfway between add and full. If it's hot outside, I suggest closer to add.

[Christina1pac]

Hi everyone!
Update and more problems... I was able to fix the problem below (or so I thought) by removing some oil. The generator ran for one more trip without problems. Then it started cranking but would only run as long as my finger was on the crank button. There was no error code flashing though. The problem was intermittent, sometimes it would crank, most times not. I took it to one service center and they did a one hour diagnostic ($175) but couldn’t find the problem so then wanted to charge me for three hour service to remove the generator and take a better look. That would be a minimum $500. I decided then to take the generator to a certified Onan shop and they told me the “stator” was broken and that it would be around $5000 to fix! They recommended replacing the whole generator which would cost around $4000 and would come with another 3 year warranty (I am 3 months outside of my original 3 year warranty ... of course!).

Now I’m a bit mixed on what to do, I have talked to some people who say that if the stator is broken, the generator will not crank intermittently, it just won’t crank at all. Obviously I don’t want to have to drop this kind of cash without a solid feeling that this is truly the problem. The generator only has 200 hours on it. I haven’t used it much in 3 years but I have maintained it well (cranking and running monthly when not used often and of course that service appointment at CW that seemed to trigger all of this).

Has this happened to anyone? Any advice before I shell out the cash for a new generator??

Christina

Originally Posted by Christina1pac

Hi all,
I took my ACE 29.3 with a Cummins 4000 gas generator to camping world for its first service at 150 hours like they suggested. Now a week later I try to start it and it won’t work. It will prime like usual and crank, but will shut off as soon as I take my finger off the crank button. Then the fault code flashes 3 times and a long pause which the manual just says “needs service.”
Any suggestions? I haven’t gone through the pain of calling the camping world service department yet.

Thanks!
Christina

[TurnerFam]

I would suggest trying something first:

when the gen cranks, continue holding the start switch, maybe for some time, then see if the same condition occurs when you let it off...

I've found that while my onan works just fine most of the time, there have been situations where, for some unknown reason, it tends to do the same as yours...
I've come to realize that code 36, or similar, is almost just a 'catch all' to the generator stopping - and not really much of any help, if there is actually any real problem to start with.

Usually, if I just restart the gen, hold the start switch for a while longer, I can eventually get it to running back properly, even if it takes a few times.

Yes, the oil level could be suspect, or something else, but my experience is that most of the time it's just a few restarts away from running just fine.

(a few years ago, SPEEDCO handled my diesel engine and diesel generator service, even while I watched - unknown to me, though, they overfilled BOTH oil chambers, rather than paying attention to the actual specified quarters provided by the manufacturer. The generator smoked terrible for some time, and we thought there was a major problem - but eventually the smoke cleared, and the generator has continued working as it should since then. I suppose the 'extra' oil was eventually purged from the system. As for the diesel engine, though, that's a different story: I left the facility, not knowing of the overfill, by probably 8 quarts, and those extra quarts wound up all over my hitch, my tow bar, and my tow car, as well as the whole back end of the coach! Crazy. I found that the Cummins diesel engine has a lower 'overfill' tube, where all this overfill was coming out while I was driving the hundred miles back home. I eventually was able to remove the additional oil and get it back to the normal reading on the dip stick, and she has run fine since.)

[16ACE27]

The stator could be "broken" without being physically broke which would prevent it from cranking. It is probably electrically broken which means no voltage or frequency output which triggers an immediate shutdown of the generator - but there should be a code when this happens.

[Bob Denman]

"Tech-Goobers", and "Sales-Goobers": the RV versions of Beavis and Butthead!

http://www.thorforums.com/forums/att...1&d=1569774187

[Lt Keefer]

Is there another Onan shop nearby? Before I dropped 4 grand on a new gennie I would look around for another repair facility or replace it with a Honda generator.

[Tom N3EQF]

As I reported in earlier responses to the OP on this issue; I had my Cummins-Onan RV QG 4000 generator fail with similar, or probably exact symptoms. These recent (mine is 5 years and 500 hours,model 4KYFA26100P, or spec "P") models no longer use the oil level sensor so I was surprised when the OP said that might have been the fix initially.

As someone else said here, the electrical diagnosis with the generator still installed in the RV can only pinpoint that the field resistance is good (18-24 ohms or higher), or as was measured by me when mine failed the resistance was infinity (open circuit). This measurement checks rotor, slip rings and brushes at once so you cannot tell what is wrong until the generator is removed from the RV and taken apart for inspection.

I took mine to Cummins-Onan in Orlando FL. The fault found was that the "block assy-generator brush" was broken. Total replacement costs, including parts and labor for removing the generator, fixing it, and reinstalling it in the RV was $1,100. Repair only took a few days all told. Great service; they even presented the broken block assembly to me to show what happened to it.

Not cheap, but certainly less than a new generator. Did Cummins actually remove the generator to troubleshoot the problem and determine that the actual stator windings had failed? Highly unusual; seems I'm missing some information.

[Tom N3EQF]

...sorry but my previous post missed the mark.

There are some resistance measurements that can be made without removing the generator, by removing the control board and checking them at the connector.

In my case, the stator resistance was fine but the field resistance was bad.
Field resistance is good at 18-24 ohms or higher, or as was measured by me when mine failed the resistance was infinity (open circuit). This measurement checks rotor, slip rings and brushes at once so you cannot tell which component is wrong until the generator is removed from the RV and taken apart for inspection.

The stator resistance should be between 2 and 4 ohms. I'm assuming this is what Cummins-Onan checked this to make their diagnosis.

I have no idea what a stator replacement costs; I guess I was "lucky" that the broken brush assy only ran me $1,100 all told. But I'm really surprised that the stator would fail on a generator that has only 200 hours on the meter.

[Christina1pac]

I’m also having a hard time believing that the stator is broken. I picked the unit up without doing anything to it and it ran fine for hours at my next start up attempt. Now though it will not work anymore cranks but won’t continue to run.

New problem, I tried to start it from inside the unit like usual and the priming light won’t come on. and it won’t show how many hours it has on the screen. It is like it is disconnected. Anyone know what could be going on? Could the Cummins service shop disconnect something? I plan to call them tomorrow to ask but thought everyone here may be faster. It will crank from the outside but will only run if I have my finger on the crank button.

Also, They did not remove the generator to test it.

Christina

Originally Posted by Tom N3EQF

...sorry but my previous post missed the mark.

There are some resistance measurements that can be made without removing the generator, by removing the control board and checking them at the connector.

In my case, the stator resistance was fine but the field resistance was bad.
Field resistance is good at 18-24 ohms or higher, or as was measured by me when mine failed the resistance was infinity (open circuit). This measurement checks rotor, slip rings and brushes at once so you cannot tell which component is wrong until the generator is removed from the RV and taken apart for inspection.

The stator resistance should be between 2 and 4 ohms. I'm assuming this is what Cummins-Onan checked this to make their diagnosis.

I have no idea what a stator replacement costs; I guess I was "lucky" that the broken brush assy only ran me $1,100 all told. But I'm really surprised that the stator would fail on a generator that has only 200 hours on the meter.

[riskmgr]

Originally Posted by Christina1pac

Hi all,
I took my ACE 29.3 with a Cummins 4000 gas generator to camping world for its first service at 150 hours like they suggested. Now a week later I try to start it and it won’t work. It will prime like usual and crank, but will shut off as soon as I take my finger off the crank button. Then the fault code flashes 3 times and a long pause which the manual just says “needs service.”
Any suggestions? I haven’t gone through the pain of calling the camping world service department yet.

Thanks!
Christina

Check oil level on dipstick. It should be 1/4” below full line as dipstick line is wrong. At 1/4” below, it’s full. If overfull, it will shutoff the generator

[cavie]

Originally Posted by 16ACE27

The stator could be "broken" without being physically broke which would prevent it from cranking. It is probably electrically broken which means no voltage or frequency output which triggers an immediate shutdown of the generator - but there should be a code when this happens.

The OP stated the the gen is cranking just not running after releasing the starter button.

[cavie]

Originally Posted by Christina1pac

Hi everyone!
Update and more problems... I was able to fix the problem below (or so I thought) by removing some oil. The generator ran for one more trip without problems. Then it started cranking but would only run as long as my finger was on the crank button. There was no error code flashing though. The problem was intermittent, sometimes it would crank, most times not. I took it to one service center and they did a one hour diagnostic ($175) but couldn’t find the problem so then wanted to charge me for three hour service to remove the generator and take a better look. That would be a minimum $500. I decided then to take the generator to a certified Onan shop and they told me the “stator” was broken and that it would be around $5000 to fix! They recommended replacing the whole generator which would cost around $4000 and would come with another 3 year warranty (I am 3 months outside of my original 3 year warranty ... of course!).

Now I’m a bit mixed on what to do, I have talked to some people who say that if the stator is broken, the generator will not crank intermittently, it just won’t crank at all. Obviously I don’t want to have to drop this kind of cash without a solid feeling that this is truly the problem. The generator only has 200 hours on it. I haven’t used it much in 3 years but I have maintained it well (cranking and running monthly when not used often and of course that service appointment at CW that seemed to trigger all of this).

Has this happened to anyone? Any advice before I shell out the cash for a new generator??

Christina

Get a seconed opnion from a second Onan shop and don't tell then what you have been told.

[Tom N3EQF]

If the runtime meter and the start switch inside the motorhome are dead, but the start switch located on the generator functions (tries to crank the motor), chances are that Cummins forgot to reconnect the cable for the inside panel. At the generator, look for a wiring harness and a connector in the line. If you find two ends with connectors, they belong together.

As for people continuing to suggest that oil level has something to do with it, I will repeat once again... later versions of the 4000 no longer use an oil level sensor as a way to prevent the unit from starting if oil is too low or too high.

I hate to suggest this, but Cummins-Onan must certainly have removed the connector from the control board and took resistance measurements to know the problem. I have no idea if the cost is unreasonable to fix what is wrong, but it seems that after all that was checked already, it isn't a fix-at-home project.

[riskmgr]

Originally Posted by Tom N3EQF

If the runtime meter and the start switch inside the motorhome are dead, but the start switch located on the generator functions (tries to crank the motor), chances are that Cummins forgot to reconnect the cable for the inside panel. At the generator, look for a wiring harness and a connector in the line. If you find two ends with connectors, they belong together.

As for people continuing to suggest that oil level has something to do with it, I will repeat once again... later versions of the 4000 no longer use an oil level sensor as a way to prevent the unit from starting if oil is too low or too high.

I hate to suggest this, but Cummins-Onan must certainly have removed the connector from the control board and took resistance measurements to know the problem. I have no idea if the cost is unreasonable to fix what is wrong, but it seems that after all that was checked already, it isn't a fix-at-home project.

My unit is a 2018 and oil level was the problem with mine after CW serviced my Gen. I reduced the oil level 1/4” down and hadn’t had anymore problems.

[Tom N3EQF]

Originally Posted by riskmgr

My unit is a 2018 and oil level was the problem with mine after CW serviced my Gen. I reduced the oil level 1/4” down and hadn’t had anymore problems.

It's not the year of the unit that matters, it is the "Spec" letter. Cummins-Onan makes changes in their specification and one recent change removed the oil level sensor.

Check your generator's part number and then look up the documentation for that specific number. Mine is 4KYFA26100P - the "P" is the specification and "P" spec has no oil level sensor.

[riskmgr]

Originally Posted by Tom N3EQF

It's not the year of the unit that matters, it is the "Spec" letter. Cummins-Onan makes changes in their specification and one recent change removed the oil level sensor.

Check your generator's part number and then look up the documentation for that specific number. Mine is 4KYFA26100P - the "P" is the specification and "P" spec has no oil level sensor.

What was happening with my Gen is that at the full mark, the oil would expand and if temp was too high. It shut down Gen. of course outside temps of 90+ and on Interstate with other vehicles, will cause the Gen to shut down without regard to oil.

[Soldier Girl]

I agree. Call Cummins! They were fantastic helping me w/an issue CW claimed didn't exist after their servicing the rig for quite a penny & another company then snagged money up front from me (yep, I was that stupid) before telling me they only diagnose (translate into English) the error code - for $156. Cummins sent me 90 miles to their Phoenix center. They were quick & professional on a major federal holiday. They even provided me w/3 days & nights of a clean, secure, electric hook up site for my rig while they worked me into their already full schedule.

Originally Posted by nosticks

Mistake #1 "took it to CW". Since they performed the service you have little choice but to take it back to them. When you eventually pick it up, start and run it a few times while there and let it run for about 15 min or so before leaving. Then find an RV service center that handles Onan's.