need help amp guage bounceing
 

my low beams are going dom then back to normal and when they go dim the amp guage bounes. i have a loose plug on the alternator could that be it? i 'm lost for answers. And i found a rust free orange swb at a auto repair shop i'm going to see if he'll sell me the doors no speaker hole and has only the oringal holes for the mirrors not like thet has the shot gun blast effect haha!

I suspect the loose alternator plug first. Having 13-14volts then 12 will cause a noticable difference in lights!