1996 Chevrolet Astro Owner's Manual - Page 122

Rear Air Conditioning (Option) You may have rear air conditioning. The rear air conditioning switch is located above the radio at the top of the instrument panel. Slide the lever toward HI for cooler air in the rear area. Slide the lever to OFF to turn the system off. If your vehicle has rear air conditioning, setting it on LO may enhance front A/Cperformance by allowing trapped refrigerant in rear lines to circulate. The system will only send cooled air if the front system is on. It can still be used to circulate air, even if the frontsystem is off. Before using the rear air conditioning, open the windows to clear the vehicle of hot air. Close the windows when using the system. Rear Window Defogger (Option) If your vehicle has this option, the rearwindow will have lines running across the glass.These lines heat your window. For best results, clear the window of as much snow or iceas possible before using the rear window defogger. To turn on the rear window defogger, find the switch marked REAR DEFOG on your instrument panel to the left of the steering column. Press the top of this switch until the lightin the switch comes on, then release it. The rearwindow defogger will only work when the ignition switch is in the RUN position. 3-4