1999 Oldsmobile 88 Owner's Manual - Page 126

yellowblue Heating Turn the temperature knob toward the red area for warmer air. To warm the vehicle up on very cold days, select the LOWER mode, turn the temperature knob to the end of the red area and turn the fan knob to its highest setting. The defogger will turn off automatically after about 10 minutes of use. If you turn it on again, the defogger will operate for about only five minutes. You can also turn off the defogger by turning the ignition to OFF or pressing the rear defogger button on your system again. Do not attach a temporary vehicle license across the defogger grid on the rear window. Rear Window Defogger Press the rear window defogger button to warm the defogger grid on the rear window. The indicator light will glow while the rear window defogger is operating. NOTICE: Do not try to clear frost or other material from the inside of the rear window with a razor blade or anything else that is sharp. This may damage the rear window defogger grid. The repairs wouldn't be covered by your warranty. 3-4