1996 Buick LeSabre Owner's Manual - Page 132

On cool, humid days, use FRONT to keep the windshield and side windows clear and to quickly remove fog, frost or ice from the windshield. After 10 minutes it will turn off by itself, orpressing the button during the heating cycle will turn it off. If you need additional warming time, push the button again. The system will then operate for five minutes before going off by itself. Do not attach a temporary vehicle license, tape or decals across the defogger grid on the rear window. If you have the the electronic touch system, adjust the TEMPERATURE lever toward WARM and the FAN lever toward HIGH. If you have the dual automatic cornfortemp system, while in the AUTO mode, the fan speed will vary. If a manual fan speed setting is selected, the fan speed will remain at that selection until the engine is turned off or another selection has been made. To turn off FRONT, press AUTO or AIR FLOW. 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 or the integrated rear window antenna, the repairs and wouldn't be coveredby your warranty. The lines you see on the rear window warm the glass. Press this button to start warming your window.