my car is an 2002 GT 89k miles.... I have an aftermarket amp installed for just my subwoofers when the bass hit the lights use to never dim... but now that has started so I replaced the battery with an optima in hopes of stopping some of the diming but it is exactly the same as before...my car drives fine and the alternator seems to work perfectly is it possible for the voltage regulator in the alternator to stop working?...but the alternator still charge and run my car??... thanks