Hi guys, im sorry if this has been asked before but i cant find anything with my exact situation anywhere. Anyway the car will idle kinda weird and it makes the lights and fan for ac fluctuate like the lights dim and brighten with the idle. im thinking maybe the idler pulley or something? Alternator and battery were tested and theyre both good. There are no codes or anything either. Thank you (: and i apologize again if this has been asked before i just cannot find anything on that.

 

I know you said the battery was tested and was good but that is the first thing I would replace for sure.
Good luck
Johan