Scott,
Easy diagnosis. On the exciter circuit, you can see the diodes and the cap at the rear of the little genny, take 4 bolts out, your done. I've only seen one diode fail, but these caps are fairly common.

This genset was about 12 years old, so he got good service out of it. The cap was shorted.

We had one at the prison that was a KTA50 cummins. It was developed as a train engine, I can't remember the HP rating of this moose, but it was pretty high. Danged nice engine. We had 1.2KW gensets powered by 3516 Cats that were pretty nice also.

All our stuff was 4,160. These were the biggest gens I ever had to work on, maintain.

I really enjoy working on an engine you walk up to with your tools [Linked Image] , creeper???? Heck, I need a ladder.

And everyone wonders why I drive a diesel (Cummins - Thank you) and wear the Tee shirt that says "I AM my own warranty station"