the voltage should be between 13.8 and 14.2, but with lights and fans and ac on it might drop to 13.4. the easiest way to replace the alternator is to remove the power steering pump and bracket first, if you clip the plastic tie strap holding the hoses to the oil dipstick tube you can leave the pump attached to the bracket and swing it out the way. there is a long bolt at the bottom of the alternator that that goes through to the bracket, it is a 12 mm head.there are 3 bolts from the front.