There are two style of blend doors one of them is right on top of the heater plenum. Here is a guide that will show you how to do it.
TEMPERATURE BLEND DOOR ACTUATOR
Disconnect negative battery cable. Remove instrument panel. See INSTRUMENT PANEL. Remove 4 temperature blend door actuator screws. Remove actuator from top of evaporator case.
1 18471 Heater Air Plenum Chamber
2 18A317 Vacuum Control Motor
3 18C433 Heater Outlet Floor Duct
4 389975-S2 Nuts
5 18A478 Windshield Defroster Door
6 - Windshield Defroster Door Crank Arm
Please let us know if you need anything else to get the problem fixed.
Thursday, August 31st, 2017 AT 2:33 PM