When trying to get A/C to turn on, we get ice cold air from the passenger vents and rear vents but the driver's vents blows ambient temp air. It occurs whether we are in single zone or dual zone mode. It occurs whether in floor or vent mode. Heater works fine. I'm guessing it is an actuator on a vent flap, I just don't know which one, where it's located, and how to get to it.