alright, my car now makes very inconsistant voltage

it used to be 13.9-14.0 all the time, now its usually in the mid low 13s, and sometimes mid 12s at idle. rarely is it ever 14.0 now.

if it was consistantly shitty i'd just say the alt was bad and replace it, but its not. could i have a bad voltage regulator? is there a way to test for it?

check your grounds..

Maybe it is just your regulator, but I would bet it's the alternator.

Sounds more like a battery than an alternator. In my esperiences of the voltage regulator going out, the voltage either sits really low or really high (some say it can jump around really fast between high and low too). Go to Checker (or whatever they have in AZ) and have them check the alternator and battery, they can do it right on the car.