Adding an automatic dimming mirror to your A6 4F Audi (and other models like A3, A4, A5) is fairly easy. There are two ways to do that.
If your car has automatic dimming side mirrors, we recommend that you get the Kufatec harness and follow the instructions that come with it. However, this is not necessary. There are six cables in the harness that command the side mirrors and disable the dimming when you put your car on reverse. The mirror itself, only needs power to operate correctly. This is why, if you don’t need this function you can simply cut the unnecessary cables and connect the others to the existing ones that go for your light sensor.
On the mirror’s side, cut all the cables but the black and the white ones:
Make sure you isolate them so they don’t touch each other. Not that something will happen but still. Now, remove the isolation from the red/black and brown/black cables that go to your rain sensor carefully.
Finally, connect the cables from your mirror to the ones that go to you rain and light sensors. Connect them as follows:
- White -> Red & Black [positive]
- Black -> Brown & Black [ground]
Isolate everything and put your new mirror on. It has a light sensor on its back so you can test whether it’s working or not by simply blocking the light with your hand.