I'm not in you guys' league but I had the clutch not kicking in. I know a low flying cloud'll stop it but I'd done the dreaded O ring job and had disturbed the connectors on the rear of the unit, evidently. I cleaned them all up with switch cleaner and pulled and shoved them a few times and uttered a mild oath. That did it. Sorry if that's not technical enough. I'm still suferring pain, though and learning. regs P.S