My charging system works 99% of the time. Under heavy acceleration at night I saw the headlights dim. I then repeated and saw the alt gauge drop off at the same time. Does not do it at idle and revving engine, only heavy acceleration from a stop. I checked the wiring and found no indications of shorting. Ground from battery is going directly to alt bracket. Grounding strap from frame to engine broken and hanging. Bad alt? Bad ground? Possessed? Ideas?