What would cause an auto dimming side mirror to stop dimming?
- Thread starter Rip
- Start date
I think I know why it's not dimming, looks like someone who owned the car before me (maybe even the dealer who sold it to me) has replaced the passenger door mirror glass with a glass that isn't heated and doesn't dim! I had a quick look on eBay and a used piece of glass is like £150+ USED! Just for the glass! I've emailed the dealer I bought the car from as the car was bought under the assumption that everything mechanical and electrical was fully functioning.
Drivers side, you can see the wires:
Passenger side, no wires:
Drivers side, you can see the wires:
Passenger side, no wires:
I think I'd double check it is supposed to be dimming on both sides first as my first S3 was dimming on both sides but I think later models were only the drivers side. The quickest way to tell is to pop the glass off and look for the wires.
It pops off easy enough if your careful by tilting the mirror out enough to get your fingers around the edge and easing it out of the spring clips
It pops off easy enough if your careful by tilting the mirror out enough to get your fingers around the edge and easing it out of the spring clips
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Even if the wiring is there it might not necessarily confirm that the standard mirror should be heated and/or dimmable. My A4 has the wiring in place but doesn't have heated mirrors, been meaning to buy some - for about 6 years!
I've just popped the mirror off and found this, so it looks like someone has tampered with it at some point as there are bare wires in there:
I'm guessing bare wires are not how it left the factory so means that someone at some point has pulled the plug off of those 2 black bare wires, and the only reason I can think that the plug has been pulled off is because they've taken the original dimming glass out and the plug was corroded on, going by that then I'm pretty sure that there WAS a plug on there at some point and it WAS connected to a piece of glass so I'm pretty sure it should be a dimming mirror.
IF the wiring was there from the factory anyway but not ever connected to a dimming glass then why would the plug be missing? Surely the plug would just have always been sat in the mirror doing nothing, no need for anyone to ever pull it off.
That and the manual states 'Dimming side mirrors' plural.
Of course I can test this by temporarily connecting the drivers side glass to the passenger side to see if the wiring actually works.
Guess I need to find a dimming glass and a plug now!
I'm guessing bare wires are not how it left the factory so means that someone at some point has pulled the plug off of those 2 black bare wires, and the only reason I can think that the plug has been pulled off is because they've taken the original dimming glass out and the plug was corroded on, going by that then I'm pretty sure that there WAS a plug on there at some point and it WAS connected to a piece of glass so I'm pretty sure it should be a dimming mirror.
IF the wiring was there from the factory anyway but not ever connected to a dimming glass then why would the plug be missing? Surely the plug would just have always been sat in the mirror doing nothing, no need for anyone to ever pull it off.
That and the manual states 'Dimming side mirrors' plural.
Of course I can test this by temporarily connecting the drivers side glass to the passenger side to see if the wiring actually works.
Guess I need to find a dimming glass and a plug now!
Well, the drivers mirror will not budge so I can't use that to test the wiring, I'm not going to risk breaking the working glass for the purpose of testing.
I guess I can test the passenger side wiring with a multimeter.
I guess I can test the passenger side wiring with a multimeter.
Yep, wiring works on the dimming plug in the passenger mirror, it shows 1.33v when the rear view mirror dims, and near enough no volts when the mirrors are not dimmed.
So yeah, that's it, problem solved, kind of. I now have to actually spend a stupid amount of money on a piece of glass :-(
So yeah, that's it, problem solved, kind of. I now have to actually spend a stupid amount of money on a piece of glass :-(
Well at least that has got to the bottom of it and the best way to find out!
I had one replaced on my 8P under warranty. Originally they said no as it was glass and that's not covered, however I argued it was an electrical item and they changed there mind and replaced it. I think the glass was about £260 on it's own
I had one replaced on my 8P under warranty. Originally they said no as it was glass and that's not covered, however I argued it was an electrical item and they changed there mind and replaced it. I think the glass was about £260 on it's own
