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Hey Alpina nut, I need your help...

1090 Views 7 Replies 4 Participants Last post by  Kaz
Or for that matter, anyone who has the Bentley's manual and can read electrical diagrams. I'm trying to figure out why my newly installed autodimming mirror isn't working. I orignally have the none-autodimming mirror in my car and I swapped with my friend's M3 mirror, which are all autodimming. I noticed there are only two wires leading into the wiring harness, while there are pins in the harness as well as 5-6 wires leading OUT of the wiring harness into the mirror. I've tried installing the fuse in fuse #24 (which controls the PDC and autodimming mirrors), but now I'm afraid that the wiring for the autodimming mirror is simply none existent in my car.

Vince, if you have time can you decipher the wiring diagram for me in the back of the Bentley's manual? I think its ELE-176 was the page...But it's the one labeled "Electrochromatic Rear View Mirror." I can't make sense of that diagram...:(
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I'd hafta go home to look at it, but I'll tell ya 2 wires ain't gonna cut it.

clown nose
autodim power
autodim control

Remember, there are 2 photosensors in the mirror that determine how dim it goes, but there has to be an outside signal to tell it that you threw it into reverse so it can undim.

If ground is shared, and all reverse does is cut power, that's still at least 3 wires.
OK, I just looked at my special-order autodim, and it doesn't look good for our Mr. HACK.

The 2 wires in the Bentley are there. So are 3 others. :yikes: Feel lucky that not all 9 wires coming out of the mirror itself are used.

All 5 of mine get wrapped up in tape and then wrapped with some of the other harnesses that live up there.

You wanna re-trade with me? At least I could likely put the autodimming to good use. :D
VinceTopasBlau3 said:
Wait a're saying yours isn't autodimming? :confused:
Mine is... so if I got the M3 mirror, it would work in my car.
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