Onan RV QG 4000 Dead

[valpo142]

The Onan RV QG 4000 Generator on my Vegas 2016 is dead. It ran for a short time and then wouldn't respond to any of the start switches. I have replaced the circuit breaker, main toggle switch and solenoid. It will crank if I short the solenoid. Any suggestions?

[16ACE27]

Originally Posted by valpo142

The Onan RV QG 4000 Generator on my Vegas 2016 is dead. It ran for a short time and then wouldn't respond to any of the start switches. I have replaced the circuit breaker, main toggle switch and solenoid. It will crank if I short the solenoid. Any suggestions?

Replace the solenoid?

I assume when you say "short the solenoid" you are jumping from the supply side to the starter side? Have you tried jumping the solenoid coil to see if it works? And is just not getting the start signal to the coil?

[valpo142]

I have replaced the solenoid. The only way I get any response is to jump from battery side to starter side.

[Pete'sMH]

Originally Posted by valpo142

I have replaced the solenoid. The only way I get any response is to jump from battery side to starter side.

I’ll bet that’s not true. Did you try applying a 12v signal to the appropriate terminal as recommended above? Obviously the generator is “willing” to start when the starter receivers current - as it does when you bypass the solenoid. The chances of having two bad solenoids back to back is minuscule. Suggests strongly that the switch or it’s wiring to the solenoid is where you problem lies.

[Beau388]

Originally Posted by valpo142

I have replaced the solenoid. The only way I get any response is to jump from battery side to starter side.

The generator will not run if the house battery power is removed. Trouble shooting my inverter, I mistakenly tripped the 100 amp circuit breaker in the house battery compartment that powers the jacks and the generator's starter motor. The generator immediately stopped and would nor start or run until battery voltage was restored to the generator's control module.

[16ACE27]

Originally Posted by Beau388

The generator will not run if the house battery power is removed. Trouble shooting my inverter, I mistakenly tripped the 100 amp circuit breaker in the house battery compartment that powers the jacks and the generator's starter motor. The generator immediately stopped and would nor start or run until battery voltage was restored to the generator's control module.

If he can jump the solenoid to run the starter that can't be the problem.

[Bill Johnson]

Originally Posted by valpo142

The Onan RV QG 4000 Generator on my Vegas 2016 is dead. It ran for a short time and then wouldn't respond to any of the start switches. I have replaced the circuit breaker, main toggle switch and solenoid. It will crank if I short the solenoid. Any suggestions?

Like everyone said it sounds like your not getting power to the small terminal below the big one you jumped. Take you meter and see if you have power at the small terminal

[16ACE27]

Originally Posted by Bill Johnson

Like everyone said it sounds like your not getting power to the small terminal below the big one you jumped. Take you meter and see if you have power at the small terminal

To be clear - when pushing the START switch/button.

[Bill Johnson]

Yes

[Beau388]

Originally Posted by 16ACE27

If he can jump the solenoid to run the starter that can't be the problem.

If power from the starter relay is not getting to the control module, then I guarantee the generator will not run. That is all I was saying.

[Scubawise]

If gas is below 1/4 tank will do that

[16ACE27]

Originally Posted by Beau388

If power from the starter relay is not getting to the control module, then I guarantee the generator will not run. That is all I was saying.

Correct, and if he left the control power lead off the solenoid when it was replaced, the control board would have no power. If the control board fuse is blown, he would have no response when pushing the start button, but if the 100 amp breaker was tripped, he could not jump the solenoid and run the starter.

[valpo142]

The Generator will only start and run when I push the emergency start button and keep it held. The minute I let it go the generator stops. All batteries are fully charged and the house batteries are new.

[Chateau_Nomad]

Do all other 12 volt powered coach items work? Lights, ceiling vent fan, etc. when NOT plugged into shore power... strictly just powered by your new house batteries?

[16ACE27]

Originally Posted by valpo142

The Onan RV QG 4000 Generator on my Vegas 2016 is dead. It ran for a short time and then wouldn't respond to any of the start switches. I have replaced the circuit breaker, main toggle switch and solenoid. It will crank if I short the solenoid. Any suggestions?

Originally Posted by valpo142

The Generator will only start and run when I push the emergency start button and keep it held. The minute I let it go the generator stops. All batteries are fully charged and the house batteries are new.

That makes no sense and does not correlate to your OP when you said "It will crank if I short the solenoid".

Starting the generator by holding the Emergency Start switch works when the house batteries are dead. If the house batteries are dead you can not "crank if I short the solenoid". No power available to do that ( unless you are applying external 12 VDC to the starter side of the solenoid).

With dead house batteries and the USE/STORE (battery disconnect) switch in STORE (open) there will be no voltage applied to the house batteries (and the generator controller) when you release the Emergency Start switch, causing the generator to shut down.

[Beau388]

Originally Posted by 16ACE27

That makes no sense and does not correlate to your OP when you said "It will crank if I short the solenoid".

Starting the generator by holding the Emergency Start switch works when the house batteries are dead. If the house batteries are dead you can not "crank if I short the solenoid". No power available to do that ( unless you are applying external 12 VDC to the starter side of the solenoid).

With dead house batteries and the USE/STORE (battery disconnect) switch in STORE (open) there will be no voltage applied to the house batteries (and the generator controller) when you release the Emergency Start switch, causing the generator to shut down.

Ted is correct. You must have 11.0 volts min in the house batteries for the generator to continue to run. The generator may crank and start at a lower voltage, but it will not run. You can confirm this by tripping the 100 amp circuit breaker in the house battery compartment when the generator is running and the converter is charging the batteries.

[valpo142]

Not plugged in all 12 volts things work find and a load test on house batteries show good.

[Pillbox]

Any codes?

[16ACE27]

Originally Posted by valpo142

Not plugged in all 12 volts things work find and a load test on house batteries show good.

OK, what's that prove in reference to running/starting the generator?

Looking back at your posts I now wonder what "solenoid" you replaced/jumped.

I suspect you have miswired your house batteries and haven't put a voltmeter on anything.

Maybe start over and be more precise with your information. Nobody here is a mind reader and when we try to be we usually fail and you get no help.

As of this point it appears:

Your house batteries are good and can supply the house DC buss
You can crank/start your generator normally IF you hold the emergency start button. But the generator dies when the emergency start button is released.
Without the Emergency Start button you can not crank/start the generator.


Based on those symptoms alone I would say the positive lead that goes to the generator through a 100 amp DC breaker is not connected to the house batteries as it should be or is not passing 12 VDC to the generator.
That breaker looks like:


Have you checked that breaker to see if it's tripped and that it is passing 12 VDC through it?
Exactly what solenoid have you replaced/jumped? Include pictures if you can.

[ducksface]

The parts cannon didn't make it work.
The guessing here didn't make it work.
If that breaker doesn't do it, take it to a pro.

What was spent on cannon load could have been spent on real repair.

Just sayin'.
There's nothing wrong with hiring a pro.