Heater Only Option (C42)
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
On non-A/C equipped vehicles, the air temperature is controlled by moving the temperature knob. Moving the air temperature knob mechanically moves the air temperature door. They are linked together by the air temperature cable. The air temperature door position determines the amount of air directed to flow across the heater core. The recirculation mode will only be available when the HVAC control assembly is in BI-LEVEL mode only.