1998 GMC Suburban Owner's Manual - Page 164

Comfort Controls Heater Control System the relative air temperature independently of the function knob setting. Move the knob to the right toward the red area for warmer air. Move the knob t o the left toward the blue area for cooler air. Mode Knob The right knob on the control panel allows you to choose the direction of air delivery. The control knob can be placed in any position between any two mode settings to blend the flow of air. /J VENT: This setting directs air through the instrument panel outlets. I). +e Fan Knob The knob on the left side of the heating system control panel controls the fan speed. The knobhas four speed positions. To increase airflow, move the knob toward HI. To decrease airflow, move it toward LO. To turn the fan off, move the knob t o OFF. Temperature Knob The middle knob on the control panel lets you select the relative temperature of the air flowing into the passenger area of your vehicle. This knob w i l l allow you to adjust VENTEIEAT Use this setting to divide airflow between the floor outlets and instrument panel outlets. HEATER: This setting directs air through the floor outlets. DEFOG: This setting directs air to the heater outlets and toward the windshield. DEFROST This setting directs air toward the windshield. +' +# w e +'