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20KW Guardian Generac does not produce 12 volts to run engine

I did not install the transfer switch, which does have a 4 amp. charger, but I assumed the Generac engine would produce its own low voltage to fire the spark plugs. Works fine as long as I have a battery charger hooked up, which draws about 3.5 amps during long term continuous operations.

Does this engine produce 12 volts for spark plugs or not???

Posted by flybikedave on


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Carl Gehrke

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The problem is that the printed circuit board inside the generator draws a little current from the battery even when the generator is not running. Over the course of a few days this can make the battery weak enough to be unable to get recharged by the built in running charger which results in not enough power to run the electronic governor on the generator. Usually the spark plugs will work even with a fairly low battery.

Most of the Generac generators come with a built in trickle charger that runs off of the transfer switch load terminals. If your built in charger isn't doing the job it's either broken or you have the wrong sort of battery installed in the generator.


Posted on Jan 26, 2009



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Generac sells a seperate trickle charger that is very easily installed in the generator to maintain the battery. Newer model generators come with the trickle charger although it does not come installed and must be installed by your Electrical Contractor. I hope this information was useful for you.


Posted on Mar 06, 2009


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