1996 GMC Safari Owner's Manual - Page 131

If you have rear heating or rear air conditioning,you will have adjustable vents in the rear of the vehicle to help direct the airflow. The rear air conditioning vents are located in the headliner at the rear of the vehicle. The rear heating vents are located next to the second and third seat on the driver's side of the vehicle, near the floor. 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 coming out of any vents that are open. Rear Window Defogger (Option) If your vehicle has this option, the rear window will have lines running across the glass. These lines heat your window. For best results, clear the window of as much snow or ice as possible before using the rear window defogger. Ventilation Tips Keep the hood and front air inlet free of ice, snow or any other obstruction (such as leaves). The heater and defroster will work far better, reducing the chance of fogging the inside of your windows. 0 To turn on the rear window defogger, find the button to the left of the heater controls with the defog symbol on it. When you enter a vehicle in cold weather, turn the blower fan to HIGH for a few moments before driving off. This helps clear the intake ducts of snow and moisture, and reduces the chance of fogging the inside of YOLK windows. Press the button until the light comes on, then release it. The rear window defogger will only work when the ignition switch is in the RUN position. 3-7