cold weather

[Qsilver7]

How about the touch method? Touch the mirror before starting to get an indication of how it feels...drive to where you are going and touch the mirror again. Is it warmer than before? Or roll the window down when you stop at a light and check to see if it is warm.

Or you can pop the mirror glass off and look for the 2 post for the heating wires on the backside...you can see them in the upper corners in the pic below (ignore the othe grayish white connector...that,,s for the auto-dimming feature):

The heated mirrors come on automatically based on ambient temps. The rear electric heater is not required. They remove fog and condensation...not just snow and ice..so they have been working when many BMW owners didn't even know it.

If you're in the USA & Canada...heated mirrors are standard equipment and has been for the last 20+ years on at least every 5/6/7/8/X3/X5/etc model...and probably most 1/3 series except for the very base model.

BTW...the washer nozzles are also heated...but I do recommend removing any build up of snow first...they don't heat up enough to melt 3" of snow from around them...nor is the washer fluid heated up so that it can burn a tunnel thru snow/ice packed around the nozzles.

Not to refute the info in the post above...can it be verified which generation BMW uses that mirror heating cycle? The info below is for the communication bus used during the e38/e39/e46/e52/e53 generation.. The new gen BMWs use the MOST & LIN busses...and many things have changed...and that could be how the new BMWs operate.