Alright so half a year ago I replaced my blown alternator at 112k miles w/ an Autozone rebuild. About a month ago I thought my belt was lose and decided to tighten it, and it should be tight enough now after all the tinkering I've done. My freakin' batter and brake light come on at the same time and they flash intermittently while I'm driving and sometimes when I'm evens standing still. The funny thing is, my AVIC-N1 voltmeter reads about 13.5 when the lights come on and eventually go up a few tenths when the lights no longer light up. Sometimes it'll spike to 15volts (and love howmy headlights and dashlights are brighter, minus the fact i'm afraid the electrical system's gonna blow). So anyway, I've checked my battery terminals and they're tight. Can anybody think of a reason this is happening, or am I'm going to have to change my alternator (PIA!!) again.

Thanks All

 

Shrug, all signs point to alternator, but you dont notice a volt drop on ur N1 so im not sure.

 

The voltage spike is just as bad as the voltage drop.
You need a new alternator.