2008 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 206

Climate Control System (Heater Only) With this system you can control the heating and ventilation for your vehicle. Temperature Control: Turn the center knob clockwise or counterclockwise to increase or decrease the temperature inside the vehicle. Use the right knob to select from the following modes: The right knob can be positioned between two modes to select a combination of those two modes. H (Vent): This mode directs air to the instrument panel outlets. ) (Bi-Level): This mode directs half of the air to the instrument panel outlets and to the floor outlets. Operation 9(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed. Turn the knob all the way counterclockwise to turn the front system off. 6 (Floor): This mode directs most of the air to the floor outlets with some air directed to the windshield, side window outlets, and second row floor outlets. In this mode, the system will automatically select outside air. 3-28