2008 Toyota Tundra Owners Manual - Page 209

07 11.20 To defog or defrost the back window, push the switch with the back window closed. The engine switch must be in the "ON" position. The thin heater wires on the inside of the back window will quickly clear the window surface. An indicator light will illuminate to indicate the defogger is operating. On some models, the outside rear view mirror defoggers and/or the front windshield wiper de−icer also operate simultaneously by this switch. On vehicles with the outside rear view mirror defoggers, the heater panel in the outside rear view mirrors will quickly clear the mirror surfaces. On vehicles with the front windshield wiper de−icer, the front windshield wiper blades will be de−iced. Push the switch once again to turn the defoggers off. The system will automatically shut off after the defoggers have operated about 15 minutes. CAUTION On vehicles with outside rear view mirror defoggers, since the mirror surfaces can get hot, do not touch them when the defogger switch is on. Make sure you turn the defoggers off when the surfaces are clear or the wiper blades have de−iced. Leaving the defoggers on for a long time could cause the battery to discharge, especially during stop−and−go driving. The defoggers are not designed for drying rain water or for melting snow. On vehicles with outside rear view mirror defoggers, if the outside rear view mirrors are heavily coated with ice, use a spray de−icer before operating the switch. NOTICE When cleaning the inside of the back window, be careful not to scratch or damage the heater wires or connectors. 179 2008 TUNDRA from Apr. '08 Prod. (OM34477U)