Temperature Control (Without Dual-Zone Climate Control)
WARNING: This page is about a different car, the 1998 Chevrolet Monte Carlo and 1998 Chevrolet Lumina. However, it is still accessible from the selected car via links, so may be relevant.
Temperature is controlled according to position of temperature selector (rotary knob) on A/C-heater control panel. An electric motor (air temperature actuator) is used to control temperature valve based on input from temperature selector. Temperature valve controls airflow through heater core as temperature selector is moved through its full travel.