2001 GMC Sierra 1500 Pickup Owner's Manual - Page 197

Rear Air Conditioning and Rear Heater (If Equipped) If your vehicle has the rear air conditioning and rear heater system combination, controls are provided to regulate temperature, location and speed of the airflow. Generally, the upper vents are used for air conditioning and the floor vents for heating. The knob can be set to any blend setting. To adjust the air temperature, turn the temperature knob on the center of the control panel. For warmer air, turn the knob clockwise toward red. For cooler air, turn the knob counterclockwise toward blue. Front Control To adjust the airflow speed, turn the fan control knob located on the left side to the desired setting. To activate the second seat control system, turn the fan knob on the front overhead control to REAR. To regulate the airflow location, adjust the right knob on the control panel. Turn the knob clockwise for floor vent airflow or counterclockwise for headliner vent airflow. Rear Control The rear control works just like the front control. It will allow second seat passengers to adjust the controls as they desire. To use the rear control, first turn the front knob to REAR. 3-10