2004 Chevrolet Astro Owner's Manual - Page 142

Directing the Airflow To direct the airflow to the rear-seating area, use the right knob located on the main climate-control panel. Generally the upper outlets are used for air conditioning and the floor outlets are used for heating. Setting the Temperature To increase or decrease the temperature for the entire vehicle use the center knob located on the main climate-control panel. The air-conditioning system on the main climate-control panel must be turned on to direct cooled air to the rear of the vehicle. If it is not on, then the temperature in the rear of the vehicle will remain at cabin temperature. Be sure to keep the area under the front seats clear of any objects so that the air inside of your vehicle can circulate effectively. For information on how to use the main climate-control system. For information on ventilation, see "Outlet Adjustment" earlier in this section. Selecting the Fan Speed Rear Heat and Rear A/C 9 (Fan): Move either thumbwheel on either climate control panel up or down to HIGH, MED (Medium) or LOW to increase or decrease the fan speed in the rear-seating area. Move the thumbwheel to OFF to turn off the fan. 3-22