I have no idea what caused this, and i have not changed nything electrical in my car in the past year almost, my car cruised fine at like 13.6-14 volts no problem, now out of the blue as i drive it just gets lower to like 13, and when i cut my headlights on it drops to 12.4, as soon as i cut my lights off it goes back to around 13.6, if i let my car sit for an hour or two when i start it again it acts fine and runs at 14, then when i get to driving it all starts again, would changing my alternator fix this or would this be something else, my headlights are stock and im not running any fancy sound system just four speakers and an aftermarket head unit, its hooked up rights its been in for over two years.

 

Your problem is most likely the alternator going out. Mine is doing the same thing as well. Mine only gets really low at idle but doesn't change the fact that the alternator is probably going out.

just an FYI you could have found your answers quicker via the search function on the forum.

 

+1
FC alternators suck.

i had a situation where my alternator died, killed my battery, replaced the alt, batt killed my alt, replaced the batt, alt killed my batt, then just replaced the batt and replaced the alt with an fd alt and everything was good! hahah

 

Sounds like your alternator has failed. But first, check connections around the thick wire to the fuse box and small plug at the back. Make sure they are not burned or loose. You may just have a bad connection.