1997 Chevrolet Astro Owner's Manual - Page 154
1997 Chevrolet Astro Manual
Page 154 highlights
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. The rear window defogger will only work when the ignition switch is in the RUN position, You can turn the defogger off at any time by pressing the button again. The defogger will shut itself off after several minutes so that the glass does not get too hot. If the window still isn't clear$turn the defogger on again. To turn on the rear window defogger, find the button to the leftof the heater NOTICE: Scraping the inside your rear window could of cut and damage the defogger. warranty Your would not coverthis damage. And don't put decaIs there, you might have to scrape them off. Press the button until the light comes on, then release it. 3-8