Fluctuating dash gauge between 11.9-13.1 mean I need a alternator or a battery??
About a month ago I was driving and car died had
my buddy put a used alternator in it for me and
today I had been out an about for a few hours
never had any issue with car starting etc came
home and had to run to store and car wouldn't
start. Had to jump start it.. looked at dash gauge
an it reads 13.1 at idle an so turned on just about
everything and the volts mainly stayed the same
but did however jump down to 11.9 at times but it
did go right back up. So is the alternator that he
put in bad? Or is my battery bad because I know
battery starts a car and a alternator keeps it
could be a defect in the alternator, or in the voltage regulator. Or maybe you installed an alternator that doesn't actually match the car.