Auto dimming rearview mirror question

[larbel]

Hi guys, I'm currently trying to retrofit an A4 auto dimming rearview mirror to my 8V S3, the part that I got is 8W0857511B, which is an auto dimming mirror with compass. There're a few wiring differences between 8V and 8W, but repin or not, I couldn't get the dimming function to work no matter what, the compass on the other hand, working just fine.

I tested it stock, repined, and even hook up just the +/- to a 12V, compass works but never the auto dimming.. So I'm suspecting the mirror itself is faulty. And it did not have any LED light up at any time, can any owner verify there should be a tiny green LED at the bottom button when auto dimming is turned on? Thanks guys!

 

[Daggerit]

My B8.5 had a small green LED at the bottom next to the button for it that would illuminate when it was active.

 

[larbel]

My B8.5 had a small green LED at the bottom next to the button for it that would illuminate when it was active.

Thanks!! But I think the B8.5 and B9 mirrors are different? The B9 has the new frameless design and almost hidden button and no visible LED at all and that's why I'm doing the retrofit on my 8V.

 

[Daggerit]

Fair enough, I'm just imagining that the actual operation would be fairly similar in terms of the LED and button to activate it?


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[wideboybloke]

Where is the almost hidden button? I can't find any button on mine. It seems to be permanently dimmed, but I can't work out whether that is actually the effect of privacy glass. If I can un-dim mine, I'd love to know how!

 

[nathanrich]

I have the frame less mirror on my 2016 S Line avant. Does that mean I have auto dimming mirror? I've not noticed.

 

[wideboybloke]

The standard spec for the B9 is auto-dimming. But from looking at the mirror you wouldn't know.

 

[larbel]

Where is the almost hidden button? I can't find any button on mine. It seems to be permanently dimmed, but I can't work out whether that is actually the effect of privacy glass. If I can un-dim mine, I'd love to know how!

Yeah.. I suspect the non-compass version might have no button at all too, the button seems to be only for the compass function anyway, it's at the bottom center of the mirror, you can't miss it if it's there.

There seems to be no mention of how to turn it off with the owner's manual too, which is strange. The Elsawin wiring diagram is even more strange for 8W... This is turning out to be much tougher and costly retrofit than expected...