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Onan 4000 not producing power but runs great!

cooperclark
Explorer
Explorer
I had the generator (onan 4000) checked out and they say it might be a bad strator that it produces no power? (I read somewhere that this generator turns off if not producing power) Now also the odd thing is that it dies immediately when I let go of the remote starter inside the RV, but runs GREAT and stays running when started from the ginny. Another wacky thing is that when the generator worked... whenever I plugged into shore power my... battery disconnect would automatically be on (allowing full power) Now I plug into shore power and alot of my electric inside has no power (Fridge,ac,microwave)but some things work and the disconnect is off,,,then when I manually turn on the battery disconnect (never had to do before it was auto when plugged into shore power) I have power to everything. Any tips or suggestions would be greatly appreciated.
Thanks
Coop
6 REPLIES 6

mikebte
Explorer
Explorer
Lots of possibility, get it checked for sure. Could be brushes worn out, stator, rotor, fuse, brakes, transfer switch, loose wire. The list goes on...

Look up trouble shooting for sure.
Or let the local Cummins throw parts at it. But you would not be here if you wanted to take it in.

TEXAS
Explorer
Explorer
Onan has been building generators since 1925. Which one do you have.

JaxDad
Explorer III
Explorer III
The older gen's like the 4KY units they work on a power in / power out basis, if you put in 12 volts you get out 120 volts.

They have circuitry that 'clips' excess voltage, I.E. if you put 13 volts in you will only get 120 out, not 130, but there is no way to boost low voltage. To protect anything you plug in, and to prevent overload the system merely shuts off power output if it's too low. So if your house batteries are low, say 10 volts, it's enough to crank and light up the motor, but too low to make power safely so it just shuts itself back off as a safety.

First put a voltmeter on the house batteries at rest, then get someone to start the Onan while you continue to monitor the voltage. If levels are good, then you may have a little surface rust on the brushes or just a poor connection.

Often just running it with the button held down for a few minutes, or several start / stops will clear it up.

j-d
Explorer II
Explorer II
By all means reply with Model and Spec. For example, our Model Number begins in "4KY" then a string of characters that in our case ends in "K," so we have a Model 4KY Spec K.

We had several generator techs on this forum, but most gave up on trying to help us because "we" (as a group) failed to provide that simple information. You may be able to get more help at www.smokstak.com but you've got to be specific.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB

ksg5000
Explorer
Explorer
When generator starts but doesn't provide power you should check the fuse/breaker on the generator - if that's OK then maybe your transfer switch is stuck.

Generator operating from switch located on generator but not the remote might indicate that you need to clean the contacts on the wire harness - also might indicate you have problem with switch.

Hope this helps.
Kevin

darsben
Explorer II
Explorer II
You give no model number so the best I can do is direct you to the troubleshooting guide at
http://www.flightsystems.com/pdf/onan-rv-troubleshooing-guide.pdf
Traveling with my best friend my wife!