1996 Chevrolet Tahoe Owner's Manual - Page 140

Rear Window Defogger (Option) If you see lines running across the rear window, you have the rear window defogger. The lineswarm the glass. To turn on the rear window defogger, press this button next to the fan controlknob. The rear window defogger will only work if the ignition switch is turned to RUN. For best results, first clear the window of as much snow or ice as possible. Do not attach a temporary vehicle license, tape or decals across the defogger grid on the rear window. NOTICE: Don't use a razor blade or something else sharp on the insideof the rear window.If you do, you could cut or damage the warming grid, and the repairs wouldn't be covered your warranty. by Audio Systems Your Delco@ audiosystem has been designed to operate easily and give years of listening pleasure. You will get the most enjoyment out of it if you acquaint yourself with it first.Find out what your Delco system cando and how to operate all its controls, to be sure you're getting the most out of the advanced engineering that went into it. The defogger will shut itself off after several minutes. If you need additional warming time, press the button again. You can turn the defogger off at any time by pressing the button. 3-9