I was given a miller 225 bobcat that runs good but wont produce ac or weld no current. I have megged the windings and seem good. I tried to excite with a 9v battery no luck. My question is does the engine alternater have anything to do with the initial voltage? nothing seems burn't and the guy that give it told me the circuit board had been changed. any ideas where to start. Do i need to ohm any thing? I have the schematic. I hate to throw it away.