I have a 96 caprice with 4.3 and battery(yellow top) is good and alternator(140amp) is good got it checked at a shop,but when its in drive and the ac and headlights are on the voltage will dramatically drop,i have to turn the ac and lights of in order for the voltage to go up??checked couple things but have no idea!! radiator support was changed since it was in a accident and pass-key fault light stays on but doesnt affect car so i just took the bulb out???anybody have any idea what it could be,also the short ground that goes to the fender next to battery is loose but that shouldnt cause it to do that?????