Rear Defroster Switch

Tihol Tiholov t.tiholov at
Tue Jan 22 15:05:47 PST 2008

Mark R. sez:
> ... I've replaced quite a few mirrors that have failed heater
elements on the newer Audis, including on my personal '00 S4.  Why would a
more modern mirror fail at such a high rate? My theory is that it's due to
the fact that Audi made a wiring change so that the mirrors are ALWAYS
heated, and the rear window defroster switch position is irrelevant.

Something similar I've got on me 2K bug - the mirrors are heated when the
angle adjustment switch on the driver's door is in the neutral position,
between left and right mirror, confirmed by a little symbol (of a heated
mirror).  This is independent from the rear defroster switch.  PO warned me
and, sure enough, the driver's mirror is intermittently (un)heated.  Oddly
enough, on me '99 bug all's as it was in the days of auld - RR window and
both mirrors are governed by the RR defr. switch

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