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Author Topic: onan microlite 4000  (Read 497 times)


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onan microlite 4000
« on: October 10, 2017, 02:25:08 PM »
My onan 4000 runs great but keeps flipping the circuit breaker after a couple of minutes. This just started about three days ago. Gen keeps running. I need help!! Also another problem that just started. My domatic frig. just screwed up. Shore power it runs fine. Gen power, it runs fine but boondocking and it wont flip over to gas. Propane is full. Need help!!!


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  • Posts: 527
Re: onan microlite 4000
« Reply #1 on: October 11, 2017, 04:30:00 AM »
Can't offer much on the genny. But, for the fridge you'll need a volt meter. Make sure you have 12vdc going to the fridge circuit board, and check all the power that you can at/on the board. It sort of sounds like the pcb may have a problem.
Marshall Alexander
2007 Fleetwood Bounder 38N DP, 2008 GL 1800 Goldwing, 2007 VTX 1300, Cessna 150 & 172, Van's RV9A.


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Re: onan microlite 4000
« Reply #2 on: October 11, 2017, 10:09:33 AM »
You obviously have the requisite 12V if the fridge operates at all. What you may not have is an air-free propane supply. With the fridge on the Auto setting, the fridge will detect if 120V is present but if not, it should attempt to light but... The fridge will make three attempts (clicks three times) to light and will be locked out (check light comes on) if lighting failed .

Why would it fail?? Most commonly, it is too much air in the gas supply which will occur if the supply was just turned on and the propane has yet to be used. Lighting the stove and letting it burn sometimes helps as the stove is not as fussy about air in the line. Sometimes when trying to start the gas operation it can take 5-6 tries by resetting the fridge (by turning off and then on) after each failure. However, if you expect an automatic flip-over and light up the first attempt without having purged any air in the propane line, you are asking a lot. Once the air has been purged it should generally light quickly enough. (To force lighting on gas without it testing for 120V first, simply leave the 'Auto' switch off.)

Another common problem with failure to light is spider webs in the burner area. Spiders love propane but their webs can disrupt the propane flow to the burner dispersing it enough to cause a failure to light. Carefully cleaning out the area is the solution.

A problem with the PCB would be a last resort type of problem, but not impossible, IMHO.
« Last Edit: October 11, 2017, 10:32:30 AM by Alfa38User »
Montréal, Canada 🍁
Snowbird, Naples Florida
Alfa Gold 38 (2000) 5ver (parked!)

"Of course I talk to myself, sometimes I need expert advise!!!"


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  • Posts: 44
Re: onan microlite 4000
« Reply #3 on: October 11, 2017, 01:13:46 PM »
thank you so much for your help! I'll give it a try and let you know if it works!