Temperature Control Lever
WARNING: This page does not describe the selected car, but rather 24 other vehicles, including the 1987 GMC Vandura Special, 1987 GMC Vandura, 1987 GMC Suburban, 1987 GMC Safari, and 1987 GMC S15 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Temperature control lever regulates the temperature of air entering passenger compartment through a cable operating the blend-air door. In "COLD" position, air by-passes the heater core to provide maximum cooling.
In other positions, air chilled by the evaporator core and heated air from the heater core are mixed to provide air of the desired temperature. In "HOT" position, A/C system should be off to provide maximum heating.