Onan 4000 won’t start

I have an Onan 4000 on my fuel 305. When I bought camper in September of 2019 generator worked fine. I took camper back to dealer over winter for warranty work and in spring generator did not work. Onan has been no help since I mentioned warranty and CW won’t return my calls to fix issue. The issue is neither switch will do anything. If I jump solenoid it cranks the motor but since I can’t get primer switch to work for anything don’t want to overcrank motor by jumping. Camper is plugged into shore power and battery is fully charged. Any thoughts are appreciated. Thanks
also there is less than an hour run time on generator
 

danemayer

Well-known member
Hi Sommer0711,

Welcome to the Heartland Owners Forum.

We have an Onan 5500 that runs off propane, so the setup is different from yours. But in addition to the switch inside, there's also a switch on the front of the generator. Maybe your 4000 also has that. If so, try that switch. If it works, it narrows the problem down. Let us know.
 

Flick

Well-known member
I have an Onan 4000 on my fuel 305. When I bought camper in September of 2019 generator worked fine. I took camper back to dealer over winter for warranty work and in spring generator did not work. Onan has been no help since I mentioned warranty and CW won’t return my calls to fix issue. The issue is neither switch will do anything. If I jump solenoid it cranks the motor but since I can’t get primer switch to work for anything don’t want to overcrank motor by jumping. Camper is plugged into shore power and battery is fully charged. Any thoughts are appreciated. Thanks
also there is less than an hour run time on generator

Since you can’t get it to prime from the main switch (are you certain it’s not priming) and you can jump the solenoid, it appears that you have a bad solenoid. It takes a few moments of cranking on ours before it fires.
The setup on these generators is somewhat different in that when you manually jump the solenoid, it may not start because of how the switch is wired to be in the on position when pressed.
 

david-steph2018

Well-known member
I have an Onan 4000 on my fuel 305. When I bought camper in September of 2019 generator worked fine. I took camper back to dealer over winter for warranty work and in spring generator did not work. Onan has been no help since I mentioned warranty and CW won’t return my calls to fix issue. The issue is neither switch will do anything. If I jump solenoid it cranks the motor but since I can’t get primer switch to work for anything don’t want to overcrank motor by jumping. Camper is plugged into shore power and battery is fully charged. Any thoughts are appreciated. Thanks
also there is less than an hour run time on generator

Check and make sure the switch is still connected. Make sure the wires are not off or loose on the back of it.
 
Hi Sommer0711,

Welcome to the Heartland Owners Forum.

We have an Onan 5500 that runs off propane, so the setup is different from yours. But in addition to the switch inside, there's also a switch on the front of the generator. Maybe your 4000 also has that. If so, try that switch. If it works, it narrows the problem down. Let us know.
Yes nothing at both switches
 
Since you can’t get it to prime from the main switch (are you certain it’s not priming) and you can jump the solenoid, it appears that you have a bad solenoid. It takes a few moments of cranking on ours before it fires.
The setup on these generators is somewhat different in that when you manually jump the solenoid, it may not start because of how the switch is wired to be in the on position when pressed.
Solenoid has been replaced, the switch on generator or inside is also the priming switch.
 

centerline

Well-known member
if neither the remote switch, or the one on the genset works, you need to check the little wire going to the starter.... the big wire carries the power to the starter and the little wire comes from the switches to carry power to the little terminal....

so if you get a wiring schematic for your generator, you should be able to see where the small wire comes from specifically, as there is obviously a disconnect somewhere between the switch panel and the starter terminal.... you NEED to get power to the small terminal on the starter for it to crank.
 

Flick

Well-known member
Solenoid has been replaced, the switch on generator or inside is also the priming switch.

Since it appears you’ve done most of what could be the problem, I’d check to see if it could be the starter relay. Try to track where your wires lead to and perhaps that will be your problem.
 

carl.swoyer

Well-known member
Sommer
Not completely sure how your generator is installed, but are there any inline fuses or breakers. Maybe a dc disconnect?

Sent from my moto z3 using Tapatalk
 

centerline

Well-known member
Sommer
Not completely sure how your generator is installed, but are there any inline fuses or breakers. Maybe a dc disconnect?

yes, we dont know how it was installed, but there should NOT be any exterior fuses in the system.... some onan generators DO have fuses under the panel at the circuit breakers...
 
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