Cummins Onan 9kw Genset voltage problem

[Kane Bounds]

I have a 9kw Onan Genset.    When I start the engine and switch it to Genset on my panel, the line Voltage jumps back and forth from 60-120.   It will then shut the Genset down, and show error code 12 on the panel.   <br />   These are things I’ve done.

Changed all fuel filters

Disconnected AC wires off generator that run to panel on the Genset then.   It runs fine no issue, but of coarse dsnt put AC power to panel.

With AC wires disconnected I checked for power while Genset is running at main breaker on GenSet.    It’s showing 60 on the red, and 60 on the black.

Anyone else ever have this problem, or have a suggestion?

Topic

[Tony Athens]

I think the answer is clear.. Either buy all the manuals and put yourself thru ONAN SCHOOL,  or hire a tech that you think can sort it out .

An outside guess from me would be something related to the very expensive voltage regulators they use 

Onan uses 1st class engines but their electronics/control systems  are extremely tough to deal with once they become “glitchy”.

If you are hands on and have the time/desire, you could remove and re-plug every connection you can get to inside the box on the top of the generator and  every external connection you can see. Spray each with WD-40 then give it a shake and re-plug.  14+ yrs  could easily degrade a connection or two and cause a glitch.  Being inside and sound enclosure adds another layer of frustration dealing with this type of trouble shooting.

[Kane Bounds]

Genset is original to the boat, so prob a 2007.   It has 2700 original hours.   It sits in a separate very dry compartment in the main cabin.   I only run the generator when I want Heat, AC, or we are night fishing.    I hadn’t run the Generator for  a couple weeks, when I started it 2 days ago I discovered the problem.    I do  not have any manuals 

 

Thanks

[Tony Athens]

What is the past history of this issue? 

What is the total history of the generator operation? 

ONAN’s alarms / software coupled to a very complex relay system that controls the shutdowns is extremely complex and is one on the reasons I personally stay away from them–Yes, not the answer you wanted.. Sorry. 

Do you have a complete set of manuals & wiring diagrams?

 

 

 

 

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