2006 Mercedes R-Class Owner's Manual - Page 216

Controls in detail Good visibility Rear window defroster The rear window defroster uses a large amount of power. To keep battery drain to a minimum, switch off the defroster as soon as the rear window is clear. The defroster is automatically deactivated after approximately 6 to 17 minutes of operation depending on the outside temperature. Activating Switch on the ignition ( page 38). Press button 1 on the climate control panel ( page 218) or the automatic climate control* panel ( page 232). The indicator lamp on the button comes on. Deactivating Press button 3 again. The indicator lamp on the button goes out. Warning! ! If the rear window defroster switches off too soon and the indicator lamp starts flashing, too many electrical consumers are operating simultaneously and there is insufficient voltage in the battery. The system responds automatically by switching the rear window defroster off. As soon as the battery has sufficient voltage, the rear window defroster switches back on automatically. G Any accumulation of snow and ice should be removed from the rear window before driving. Visibility could otherwise be impaired, endangering you and others. 215