The belt to come off. Check ur voltage on batt when car is on then turn on heater (big elec load) see if ur volts drop then come back up. That will eliminate the alt being the a$$hole. Next, If ur worried bout pulley lining up cut a piece of string 2ft long and place one end on the inside rib of alt pulley and the other end on the inside of the ur pulley rib where belt is supposed to go. It should be a straight shot if ur string is at an angle ... That sucks. Hope it works out