The generator starts but produces no ac. Did the tests that Flight Service walked me through and the results indicated a bad rotor. Has anyone ever been able to remove the rotor form an Onan BGEF generator without removing the generator from the motor home. We did clean brushes, slip rings, etc. Stator tested ok. Rotor tested ok in stationary position but ohms fluctuated wildly when rotor was turning.
Jim

Jim did you change the brushes and how did you clean the slip rings?

Reason I asked is many times over the years the brush spring looses pressure and while testing stationary looks good rotation looks bad.

Did you test the voltage at the brush contact while running? that would tell you more than resistance testing.

Ed, we took the brushes out and cleaned them but I don't know what the slip rings are or look like. The brushes seemed to have plenty of spring to them. Today, I started up the generator and voltage at any outlet was about a steady 123 with no load. Until I learn how to clan the slip rings, I won't do any more. A California company that rewinds rotors told me that the rotor would show wide fluctuation while it was rotating. So maybe I don't need a rewound rotor. As you can tell, I don't know much about this stuff. Any help would be appreciated

Jim

Just watched a U tube video on how to clean slip rings. Flights Service guy named Tom produced it. Now I know what they are, where they are and how to clean them. Flight Services sells something called a Slip Stick that makes cleaning them a 30 second job. Will order new brushes while I'm at it Will also test voltage while it's running.

Thanks Ed

Jim

I would agree with Ed. Be sure the slip rings are clean and brushes are good. This has been the most common problem I have seen with gensets that do not get regular use. Same thing happens with alternator slip rings.

Sometimes after running awhile the brushes will polish the rings clean but giving the rings a good cleaning first should be the ticket.

Jim Speaking of GTG's southern Indiana has lots of lakes and cool places to have one, and lots of us Barthers' are within a day drive. Good Idea???? Nice weather!

quote:

Originally posted by Steve VW:
I would agree with Ed. Be sure the slip rings are clean and brushes are good. This has been the most common problem I have seen with gensets that do not get regular use. Same thing happens with alternator slip rings.

Sometimes after running awhile the brushes will polish the rings clean but giving the rings a good cleaning first should be the ticket.

We bought a Slip Stick and cleaned the slip rings. they appeared to be pretty dirty. Some small pieces of copper actually came off on the slip stick. During the cleaning, the generator ran perfectly. We also bought new block and brush assembly. The company sent us the wrong one so we used the brushes and springs from the new set and put them in our old block. The new springs were about 1/4" longer than the old springs. Then the generator wouldn't start. It would run as long as we had our finger on the start switch but shut off as soon as we took our finger off. Took the brushes and block off, had the block upside down, put it back in. Genny started ran fine then stopped again in 10 minutes. this time we found that one of the brushes was sticking in the block. Put old brushes and old springs in old block. Same thing. Would run for a while and then stop. Now it won't even do that. Will only run while finger on the start switch. Oil level is as it should be. Gas tank is 3/4 full. Damn. It's a Onan BGEF. The thing that is strange is that it ran fine while I was cleaning the slip rings and had the old block and brush in it. As soon as I put the new springs and brushes in the old block, it would only run as described above. Any help would be appreciated.

Jim

Ah the joys of old electromechanical maintenance...

On Wed I changed the oil and filter in the coach. Started, checked for leaks, etc. Had 13v showing on the gauge. Thursday morning we got ready to leave for a visit with my Dad in the UP to pull his boat out for the season. Started up, only 12v showing! Went to get fuel, restarted, still no charge. Drove back home.

I checked a few wires, determined the problem was the alternator. Removed it and thought maybe cleaning brushes might get me down the road. I removed the brush holder and found massive corrosion all over the brushes and regulator circuit board. So much for that. I got a replacement alternator by 8am Friday and we were on the way by 930am.

It sounds like you have some nested problems. It sounds like the brushes were some of the problem, but something else has changed.

I have a love/hate relationship with Onan generators. I have seen several with intermittent problems. Most are like yours, where the engine will run but still won't generate. The fact that yours will run with the start switch only indicated the engine is ok but there is a logic problem. The last time I left Hillsborough my gen would not run except with the start button held down. I latched the switch down and drove it to Port Charlotte.

With the start button held on, power goes directly to the engine. When the button is released, the logic board takes over. As long as it sees no error conditions, it allows the engine to run. If low oil pressure or high temp exists it will shut down. Running with the start button held overrides the logic board but may allow damage.

Sooo... It sounds to me like you have the Onan Black Magic syndrome. Either the logic board is failing intermittently, or the wiring/sensors are loose or corroded. Playing with the brushes may have disturbed the sacred Onan dust and dirt. Worst case it may be the expensive/unrepairable logic board.

Be sure the brushes are free to follow the now clean slip rings and are connected securely. Check all other connections, wiring harnesses etc for some fault. Lasr resort you may need a logic board. Fair warning, some are no longer available and those that are available are usually non returnable.

I have found Onan generators to be frustrating to troubleshoot. Good luck.

Fortunately, we have some time. We usually don't dry camp and sinc it's now cooler, don't need the roof air to stay comfortable while driving. The dash ac system is sort of not there.
Are there options for more dependable generators? I've thought about buying two Honda 2000 generators, putting them in the cabinet together and wiring them up. But I don't know if they're made for the vibration and bumps of driving down the road.

A friend of mine just bought a Predator 3500 inverter generator from Harbor freight . He studied the reviews on it and it seems to be a pretty good inexpensive generator . Time will tell .

https://www.harborfreight.com/...generator-63584.html

quote:

Originally posted by Harold,Cat&Sam:
A friend of mine just bought a Predator 3500 inverter generator from Harbor freight . He studied the reviews on it and it seems to be a pretty good inexpensive generator . Time will tell .

https://www.harborfreight.com/...generator-63584.html

I have a 3500 watt generator, not this brand, and it will not start my 15,000 BTU Coleman a/c!!! Kicks out circuit breaker every time!! Tried it when my Onan was not working.

I've been following this and have to put in my 2 cents. My old Onan starts and runs fine, thanks to BillyT troubleshooting it at a GTG a couple years ago, but it won't start the AC when first fired up. When I turn on the AC it pulls the genny down almost to killing it then pops a breaker somewhere and the genny resumes rpms. After a few seconds the power comes back on. As an experiment I went out and increased RPM with my hand while Suzie turned the AC on and it came on fine. Once on the AC will run fine. Trying another thing, I let the genny run for about 30 minutes and it will start the AC. When Billy worked on it he did reduce the RPM slightly, because I was getting 63 htz and he lowered it to 60. I don't have a meter to check it now and I don't want to just raise the RPM without knowing how many htz I'm getting.

Perhaps I should have added to my above post, that the Onan works fine when the A/C comes on it does not even stutter a bit. The Onan is 4500 watts.

The 3500 is a Generac that I bought when the power was out in the neighborhood for 2 weeks.

I don't know if this genny ever started the a/c or not. Jerry may have used shore power only when using the a/c. Having said that, 4000 watts might be a little marginal when trying to start a 13,500 a/c, especially if the genny is old and not working up to par or the a/c is old.
I have also read that portable generators are designed to be used outdoors where they get decent cooling from the air. Putting a portable generator in a cabinet, even though the cabinet does have cooling from open fins on the bottom, is said by some to be a bad idea. One guy installed a portable generator in his rv but also put a fan in the cabinet to keep it cool.
The only info I have on the a/c is that it is a Duo Therm Royale Penguin model 610115.103. The a/c compressor rated load amps is 12.4 and the a/c fan motor is rated load amps of 3.1. But, isn't the initial amp load much higher upon start up?

quote:

Originally posted by Jim and Tere:
I've thought about buying two Honda 2000 generators, putting them in the cabinet together and wiring them up. But I don't know if they're made for the vibration and bumps of driving down the road.

As much as I love my Honda generators I would make a few comments. Honda does not recommend running a portable generator within 3 ft of anything. I have heard of several failures of enclosed generators due to insufficient cooling air.

That said, you may recall that I installed a Honda genset in my Regal. I used a sheet metal plenum to funnel hot air out and 2 exhaust fans to assist. I had no cooling issues.

https://www.barthmobile.com/eve...633949187#9633949187

That generator is a 3000 watt invertor model. It ran my 13,500 Btu roof air no problem.

If you do not intend to enclose them, ie store them and set them outside to run, I would not blame you for chaining two 2000s. The 3000 weighs 148 lbs and is at the limit of "portable" for me. I also have a Honda 2000 watt invertor genset. It is a great unit, the size of a sewing machine case and not so heavy. I have used that one many times for portable tool use and at my deer camp.

The Hondas are quite expensive. Now that Chinese knockoffs are available I would consider them at half the price! I would definitely go with an invertor type.

Either way, it may still be more economical to fix your Onan if major parts are not needed.

Now that you have a Barth again it is only reasonable that you should have a GTG to celebrate. Just let us know when and where, can't wait.

Have Barth, will travel