Alpina nut to the rescue! 
Hmm, we are looking at ELE-178 right? That seems to be the autodimming mirror, cos like Kaz said, we have a photosensor (or light diode) in A22. However, I am highly suspicious that ELE-178 is complete though, cos it shows only 2 wires: RED/BLACK and GREY/BLACK/YELLOW. The R/B one leads to a 5Amp fuse and the G/B/Y leads to the General module (ELE-133, 2 of 6).
Are you able to identify these two wires? If so, good. Set them aside and tell me what are the colours of the other wires? Take a pic or something.
Now back to ELE-178. Something even more interesting. See that white arrow pointing to the right of the page? The one between A22 and F67. Now that is a crucial CLUE there. Bentley did not provide further information where this signal is being tapped to. Cos this might lead to the dimming function.
Hmm, we are looking at ELE-178 right? That seems to be the autodimming mirror, cos like Kaz said, we have a photosensor (or light diode) in A22. However, I am highly suspicious that ELE-178 is complete though, cos it shows only 2 wires: RED/BLACK and GREY/BLACK/YELLOW. The R/B one leads to a 5Amp fuse and the G/B/Y leads to the General module (ELE-133, 2 of 6).
Are you able to identify these two wires? If so, good. Set them aside and tell me what are the colours of the other wires? Take a pic or something.
Now back to ELE-178. Something even more interesting. See that white arrow pointing to the right of the page? The one between A22 and F67. Now that is a crucial CLUE there. Bentley did not provide further information where this signal is being tapped to. Cos this might lead to the dimming function.
The HACK said: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...
