2001 GMC Yukon Owner's Manual - Page 171

Heater and Air Conditioning Comfort Controls (If Equipped) Mode Knob The right knob on the control panel allows you to choose the direction of air delivery. PANEL: This setting directs the air through the instrument panel outlets. BI-LEVEL: Air is delivered through the instrument panel outlets and the heater floor outlets. The air flow can be divided between PANEL and HEATER depending upon where the knob is placed between the settings. Pressing the A/C button while in this mode causes cooler air to come out of the instrument panel outlets and warmer air to come out of the heater floor outlets. Fan Knob The knob on the left side of the control panel adjusts the fan speed. To increase airflow, turn the knob clockwise. To decrease airflow, turn it counterclockwise. To turn the fan off, turn the knob to OFF. Temperature Knob The middle knob on the control panel lets you select the temperature of the air flowing into the passenger area. Turn the knob clockwise toward the red area for warmer air. Turn the knob counterclockwise toward the blue area for cooler air. HEATER: This setting directs most of the warmed air through the heater floor outlets as well as some air through the windshield defroster outlets and side window defroster outlets. BLEND: Airflow is delivered through the heater floor outlets, the windshield defroster outlets and the side window defroster outlets. The air flow can be divided between HEATER and DEFROST depending upon where the knob is placed between the settings. The air conditioning compressor may run to dehumidify the air to prevent window fogging. 3-3