Generator load problem

[VC63]

Hi Everyone,

I am having a problem with my gas Onan RV QG 7000 generator model 7HGHAB-900E. I did an oil change today and after I wanted to check to make sure everything was operating properly. The gen. started and ran well. I turned on the A/C and the gen. tried to rev up for the load but could not and stopped running.

I checked everything I could think of including flipping the breakers in the RV and on the genny. I checking the voltage at the transfer switch and at an outlet. It all was at 120 volts until I tried to turn on the A/C. Once it quit, I was only getting under 100 volts after restarting.

The generator was showing a code 13. That is a under voltage fault. Controller unable to maintain rated voltage. The corrective action is to reduce the number of appliances. This generator can run everything in my RV at the same time.

Once I restart the gen. again the voltage comes back up to 120 and will run the microwave, tv and water heater but not the micro. and the W/H at the same time. It will stall out. When I try to start the A/C it stalls out.

I looked on line and on YouTube but no good answers about this problem. I suspect the control board but it could be something else. I even drained out a little oil because I read that when it is correctly full (2 quarts) it will not run right. That did not work. I am baffled.

I exercise the unit every 2-4 weeks and run both A/C when I do. I did this about 2 weeks ago and everything worked well. I triple checked to make sure I didn’t pull loose a wire while changing the oil and everything looks ok.
If anyone has any ideas I sure would apricate them. I hate to take it to Cummins I know that will be at least a $1000.00 trip (yikes)

Does anyone know the phone number for Onan technical support and where the control board is located.

2012 Tiffin Open Road 50 amp service

Thanks as always
VC

[twinboat]

Sounds like a fuel problem.

Could still be gummed up carburator but, you say you run it often. Check the fuel lines for loose clamps, kinks or perforations.

Get it running, let it stall and then open the carb bowl drain to see if it's empty.


More then 1/4 tank of gas ?

[Gary RVRoamer]

If the generator cannot increase engine power to handle the increases electrical load, the voltage falls and it shuts down. The governor responds to the demand by increasing fuel flow, so that's where you need to start looking. Did you change the fuel filter too? Or the air filter? (more fuel needs more air to burn it).

[randomledder]

Verify it is running on both cylinders. The magnetos have been know to have issues. They will still run reasonably smooth on one cylinder.

[THenne1713]

Generally, engine unable to handle normal LOAD implies LEAN condition, and is often a symptom w/ ONAN of a FAILING FUEL PUMP. While possible fuel filter, that is very rare because RV GEN pump pickup does NOT sit on bottom of tank where debris settles.



If your model carb has the BOWL DRAIN SCREW, allow to cool after it dies, then open/ loosen** screw and drain to a small container, and see if maybe a FUEL issue (** Believe I read screw does not require removal to drain, just loosening?). IS good practice to run GEN annually under 50% load for 90-minutes; if it does OK, you can have more confidence in performance (= a standard test for EMERGENCY GENS) Hope this helps?