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Onan Generators

Onan 12.0 MDJC

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Old 03-26-2008, 05:06:47 PM
Doug101 Doug101 is offline
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Default Onan 12.0 MDJC

I have a1980 onan 12.0 mdjc-3cr/2268ab. The engine seems to run perfectly but over the last while the voltage output has been intermittent. Sometimes have to restart several times before voltage comes on. Had noticed previously that sometimes the volt meter spiked wildly and then settled down.
I think it might be a voltage regulator problem. I'm told that there is no test to verify if it is the voltage regulator and that I must buy a new one but if it does not solve the problem it cannot be returned because it is a pc board with no return/no warranty. The best I can tell the part number is 305-0589. Would this be a correct number? Best place to buy? Any ideas on this problem. The set has about 3000 hrs but looks in decent condition with little rust and the diesel runs very well.
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Old 03-26-2008, 06:22:04 PM
Gunny Gunny is offline
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Default Re: Onan 12.0 MDJC

It could very well be a voltage regulator, then on the other hand, it might be a loose wire connection. Ensure that all wire connections are good, pay attention to the ones going to/from the voltage regulator, including the ones going to a remote voltage adjustment pot, if any. If you have a voltage adjustment potentiometer, take it out of the circit and see if it is the cause. If you have eliminated any problem with a connection, all that is left is the voltage regulator. Best place to get one is Flight Systems (717)932-9900. Better price, better warranty and better product than Onan.
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Old 03-26-2008, 06:25:53 PM
Ben Clarke Ben Clarke is online now
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Default Re: Onan 12.0 MDJC

Try flight systems they are great!! The price is right, quality #1 also have a tech line and can be a real help.
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