1999 Chevrolet Blazer Owner's Manual - Page 155

yellowblue BI-LEVEL A/C: This setting cools the air entering your vehicle and directs it through the heater floor outlets as well as the instrument panel outlets. VENT: This setting directs most of the air through the instrument panel outlets and a small amount through the floor outlets. The air conditioning compressor is not working when VENT is selected. HEATER: This setting directs most of the warmed air through the heater floor outlets and some air through the windshield defroster outlets. BLEND: Airflow is divided equally between the heater floor outlet and the windshield defroster outlets. DEFROST: This setting directs most air through the windshield defroster outlets and some through the heater (floor) outlets. Fan Control The knob on the left side of the electronic climate control panel controls the fan speed. To manually increase airflow, move the knob clockwise. To manually decrease airflow, move it counterclockwise. OFF: If the knob is in OFF, outside air will still enter the vehicle, and will be directed based on the position of the mode knob. AUTO: If the knob is in AUTO, the fan speed will vary as the system maintains the selected temperature. Electronic Climate Control System (If Equipped) 3-3