1996 GMC Sonoma Owner's Manual - Page 112

Mode Knob ,Thelower knob allows you to choose the direction of air delivery. Optional Climate Control System OFF: This setting turns off all beating functions. Some outside air will still come out of the heater outlet whenever the vehicle is moving forward. /J VENT: This setting directs airflow through the instrument panel outlets. heater floor outlets and the instrument panel outlets. a +e HEATER: This setting directs warmed air through the heater floor outlets and windshield defroster outlets. BLEND: Airflow is divided equally between the heater floor outlet and the windshield defroster outlets. %?DEFROST This setting directs m.ost air through the windshield defroster outlets.and some through the heater outlets. + ' +# w e + setting directs air through the BI-LEVEL:' This +e Fan Control The switch with the fan symbol changes the fan speed. To increase the fan speed, move the switch upward toward HI. To decrease the fan speed, move the switch downward toward LO.