For a while my voltmeter has been goin up and down. Every once and a while i'll notice my battery idiot light on and my voltmeter would be down below charging. At night I would notice because my head lights would dim. Without faile though, it would always go back up a few seconds later. It has dont this for a couple years and i never did anything because my battery never died. Finally the other night it went below charge and never went back up and it died. My alternator is a crap rebuilt job, but it's less than 2 years old. My battery is pretty new too and I dont think it's that because I recharged it and it seems to be holding it. Does it sound like a connection or a ground maybe? What should I do?