Originally Posted by Iamfink2
When you turn on your rear defroster the side mirrors heat up as well.
Not true. According to the service manual, the mirrors heat up any time the ignition is on:
DESCRIPTION
The exterior mirrors are equipped with heater elements located
behind the mirror glass (1) on each sideview mirror. With the
ignition switch turned to the ON/RUN or START positions, the
sideview mirror heater elements are powered. The heater ele-
ments behind each sideview mirror cannot be repaired. If
faulty or damaged, the entire sideview mirror assembly must
be replaced. For complete sideview mirror removal proce-
dures, see sideview mirror removal in this section. Refer to
Page 8N-72.