Function Control Lever
WARNING: This page is about a different car, the 1995 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
Function control lever can be placed in OFF, PANEL, PNL/FLR, FLOOR, FLR/DEF or DEFROST position. The function control lever operates a cable connected to cams that operate floor/defroster and panel doors.
Outside/recirculation door is controlled by a vacuum valve and vacuum motor. When function control lever is in the OFF position, vacuum is applied to outside/recirculation door vacuum motor to shut off outside airflow. When function control lever is in any other position, vacuum is not applied to outside/recirculation door vacuum motor and outside air is allowed to enter the vehicle.