Onan Popular Questions, Answers, Tips & Manuals

Check for shorted stator windings and/or armature.

Sounds like there's an open in the battery wiring circuit.

replace the dead battery

check the current draw from the machine being a 4000 watt machine if you are drawing 4000 watts it is overloaded as that is the surge power available not constant power which is around 3500 watts that would account for the requirement of fans to keep it cool even if It is not 4000 watt what ever capacity it is it is running in an overload situation

check for bad battery, loose terminals ,dirty terminals , faulty starter relay if it is not starting check for oil level is correct ( low oil level sensor turns off ), diesel -air in system

Onan's website has them. I don't think you can get one for free, though.

Donna every 150 hours is recommended oil/filter change. Below is a link to your manual. PRESS THE HELPFUL BUTTON http://power.cummins.com/sites/default/files/literature/rv/F-1123-EN.pdf https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwizkMmJseTKAhWE3iwKHfWYB-wQFgggMAE&url=http%3A%2F%2Fwww.alpinecoachassociation.com%2Ftech%2Felectrical%2Fonan_generator.pdf&usg=AFQjCNEUMhkxC21qqFulwZzDRJPdxAAmdw No Start No Run Onan 4000 Microquiet H040676255 4KYFA26100K Cummins Onan RV Generator Parts Manuals

Was every thing oily in the generator? It sounds like you may have lost a bearing in the engine. You definately don't want to spend without finding out where the play is that let it rub. It will do it again. Check and make sure that the rotor isn't loose on the motor shaft. Make sure the bearing housing on the end of the rotor won't let the bearing move around in it.

Some engines have a low oil cutoff switch. If the oil level drops to a certain point it kills the engine. Your oil level may be close enough that after starting and running for a little bit the level drops enough to kill the motor. After sitting for awhile the level rises enough to allow the engine to run again check the level and add oil if necessary. Hope this helps. Bob

SIMPLE Onan Generator Fuel Pump Test and Replacement Tips

Odds are that the ignition switch or wires are giving you the grief. Thee unit will probably be getting spark power through the starter solenoid (look for a wire there) but when the solenoid is not activated, there will be no ignition power. Take your time and trace it down. You'll get it. Cheerfuls!

Hello Martin, Your generator might have a low oil pressure shutdown switch. First check the oil level. If oil level is low, fill oil to proper level. If oil level is fine, I would install an auxiliary oil pressure gauge . If oil pressure is normal, I would change the oil sender unit. If oil pressure is low, I would change the oil pump.

Hi John: Sounds like you may have a bad starter. Can you bench test it?

Have you checked the fuel quality?

low oil shutoff,tank filter,sticking float

You may be reading the code wrong, Code 33 shows up as blink 3 pause blink 3. This means it has a lower level code fault. To access the real code. Press the stop button 3 times fast within 5 seconds and re-post what the code is please. It may blink pause then blink again, that is the lower fault code that will help diagnose the problem.

check for a faulty sump oil switch . check for faulty coil ( magneto on the flywheel) as the time it runs suggests that it is breaking down internally.

If it is backfiring even during idle, there are a couple of possible issues. Check the obvious and least expensive first. Make sure you have correct OEM spark plugs, check ignition wires. Then check the ignition coil and trigger module, there is a procedure for doing that in the Cummins Onan manual. A manual can be obtained from http://www.advanced-power-technologies.com/ or local Onan RV dealer. This will give you the ignition coil resistance and the ignition module resistance. Also has anyone messed around with the carb, or has it sat for long periods, too lean a fuel mixture can cause backfiring. Good Luck ;)

Check the ignition circuit, and trigger coil for correct resistance on the trigger coil, and the ignition coil. The trigger coil is a small module on the engine shaft near the flywheel.

Check the entire fuel system, pump pressure, carb bowl for dirt, carb jets clear. fuel filter. Do a compression or leakdown test on the cylinder.