2002 A6 Avant 3.0
 

Can someone tell me how & where to turn on/off Exterior heated mirrors?

I went through the owner's manual and still can't find it. Just got the car last Thursday.

Does the Defrog/Defrost button activate the mirrors to be heated?

My understanding ( I haven't gone out with a multimeter to confirm this) is that the heat is applied to the mirrors when the front defrost button is On. My experience is that they are on at other times as well, probably when I turn on the rear defrost. It could also be when the car decides to turn them on.

However, there is no direct way to disable this feature. Indirectly, you could remove the mirrors and wire in a switch. Why do you want to be able to control this?

Bob

No I don't want to disable it ... just curious to know when and under what condition the heat on the outside mirrors are 'on'...

Just found out once the engine is started the mirror heat is on automatically...