There are two actuators in the dash and two in the rear for the rear heat/AC. The rear ones are a pain but not too bad to replace. The front heat/AC also has two actuators. One for the right side and one for the left side. The passenger one can be accessed (see video link). Don't let this guy fool you, this is a nightmare from hell to replace. The part is about $30 bucks. The drivers side actuator cannot be accessed without pulling the dash and that would be your worst nightmare and if the dealer does it you're talking big $$$...