1993 Cadillac DeVille Owner's Manual - Page 155

3. Push the switch. A light will come on to tell you it is working. The system will go off after a four minute heating cycle (two minutes if you shift out of "P" (Park) within the first two minutes of the cycle). If you want it to cycle again, push the switch. It will go on for two minute cycles after that.If it has cleared your windshield before the cycle isover, you can turnit off by just pushing the switch again. In warm weather the heatedwindshield system helps keep thevehicle's interior cool by blocking much of the sun's heat producing radiation. The system's solar control properties help reduce interior fading. also There is a metal film in the windshield which will block some radio or out microwave signals.Therefore, the heated windshield will reduce the useful range of devices suchas garage door openersand radar detectors. (In certain states radar detectors legal.) are Rear Window Defogger To get fog or ice off the rear window, push the Rear Defogger button. With it, your rear window and both outside rearview mirrors are warmed. To turn it off, push the button again. After 10 minutes, it will go off by itself. To make it go longer, just push the button again.