2002 GMC Sonoma Owner's Manual - Page 157

Mode Knob The right knob on the control panel allows you to choose the direction of air delivery. OFF: This setting turns the system off. Some outside air will still enter the vehicle whenever the vehicle is moving forward. If the air entering your vehicle is warmer than desired, turn the temperature knob fully counterclockwise and turn the mode knob to vent mode. (Vent): This setting directs most of the air through the instrument panel outlets and a small amount through the floor outlets. (Bi-Level): Air is delivered through the floor outlets as well as the instrument panel outlets. (Floor): This setting directs most of the air through the floor outlets and some air through the windshield defroster outlets. (Blend): Airflow is divided equally between the floor outlet and the windshield defroster outlets. (DEFROST): This setting directs most air through the windshield defroster outlets and some through the floor outlets. Optional Climate Control System Fan Control The knob on the left side of the climate control system panel operates the fan speed. To increase airflow, turn the knob clockwise. To decrease airflow, turn it counterclockwise. 3-3