1994 GMC Sonoma Owner's Manual - Page 117

Air Vents You will find air vents in the center and on the sides of your instrument panel. You can move the vents to direct the flow of air, or close the vents altogether. When you close a vent, it will increase the flow of air corning out of any vents that are open. Heater Controls If your vehicle does not have air conditioning, your heater controls will look like this. The switch on the righthand side changes the fan speed. To increase the fan speed, push the switch upward toward HI. To decrease the fan speed, push the switch downward toward L O . The upper knob changes the air temperature.Turn the knob right (clockwise) for warmer air.Turn the knob left (counterclockwise) for cooler air. The lower knob changes the heater function and determines which outlets the air will flow through (instrument panel, defroster, heater, etc.). 3-3