i took my underdrive pulley's off today because my car has not been fully charging. it fluctuates often, causing an assortment of problems. i thought putting the stock pulleys back on it would fix it, but not the case. my alternator is not a month old yet. so i feel like it is ok. what else could cause it not to fully charge? thanks,
Get the car up to operating temp. Get a volt meter and put it on Volts DC, then see what the battery terminal voltage is while idling. It should be about 14-15vdc. If it's less then it could be a bad voltage regulator. I'm going through this right now.