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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: frankinberry on April 26, 2013, 06:34:22 PM

Title: Kolher generator problems
Post by: frankinberry on April 26, 2013, 06:34:22 PM
Hello, I have a 1993 Bluebird bus with a 12.5 Kohler generator powered by a Yanmar diesel motor. The generator output is only 86.4 volts on each leg. Voltage reg. tested ok. Any ideas? Thanks
Title: Re: Kolher generator problems
Post by: wg4t50 on April 26, 2013, 06:57:41 PM
If the voltage regulator is OK and you only have 86 volts per leg, clearly you have either loose wiring or a bad meter, might be possible the regulator adjustment pot was turned to a lower voltage.  I would not bet the farm on that good regulator.
One other possibiility, engine running too slow, not up to 60 herts/1800 rpm ?
Dave M
Title: Re: Kolher generator problems
Post by: frankinberry on April 26, 2013, 07:09:14 PM
Meter ok, 1800rpm ok, wires ok, generator was running fine - than a slight flicker in the lights for about 45 min. When I started it next day - no more than 86.4 volts both sides. Can the alternator on the gen.engine have an effect on the gen. output?
Title: Re: Kolher generator problems
Post by: luvrbus on April 26, 2013, 07:19:08 PM
Dave is the expert on the generators here but I had a problem with my 12K and the regulator would test good after about 2 days of testing at Wrico they found the fuse to the regulator to be bad and they never figured out why it would produce 80v on each leg with a bad fuse they had theories but I believe most where just guesses 
Title: Re: Kolher generator problems
Post by: gus on April 26, 2013, 10:37:22 PM
One good possibility is a failed field rectifier, happened to me. It is pretty sensitive to heat and voltage surges.

However, if it failed you probably wouldn't get more than 30v or so, won't hurt to check it out though.
Title: Re: Kolher generator problems
Post by: frankinberry on April 27, 2013, 03:33:08 AM
Thank you all for the help