1993 GMC Suburban Owner's Manual - Page 157

K2112 Youcan tell if yourvehiclehasthisoptionbylookingattherearwindow. you see, lines running across the glass, you have it. Thesearethewires which heat.your window. If For best results, clear the window ofasmuchsnoworiceaspossiblefirst. To turn on the rear window defogger, find the switch,marked WEAR DEFOG on your instrument panel, just below the heater system. Press the right side oftheswitch,with-thedefogsymbol on it, until the light in the switch comes on,thenreleaseit.Therearwindowdefoggerwillonlywork if theignition switchisturned to RUM. Youcan turn the defogger off atanytimebypressingtheleft,lightedside of theswitch.Thedefoggerwillshutitself off afterseveralminutes, so thatthe If thedefoggershuts off, andthewindowstill glassdoesnotgettoohot. isn'tclear,turnthedefoggeronagain. 3-1 1