A rear window defroster is an embedded or applied electric heating element that warms the rear window to rid the glass of fogginess and frost or loosen snow and ice. The defroster is usually activated by a button on the console or dash and sometimes with a remote start.
When activated inside the rear glass, a thin wire element, usually a series of lines, heats the rear window for a limited time.
A rear window defroster is considered a convenience rather than a safety feature, so the federal government does not mandate it. However, it does improve rearward vision when in use and is a popular feature. Pickup trucks are about the only passenger vehicles that don’t consistently contain this feature, as the rear windows are vertical, making it difficult for moisture to settle on the surface.
A soft top on a convertible or SUV may not have a rear window defroster if it has a soft plastic window.
See also backup camera, heated mirrors, rear window wiper
