Internal mirror wiring for dimming mirror

HPsauce · #1 8th July 2021, 10:20 AM

Quote:

Originally Posted by pete-p

I wonder if this is to cancel the dimming when the interior lights come on?

That's the sort of clever feature that you'd expect on an '8!

Though personally I'd probably avoid using that input unless you're doing a full OEM install - you just never know how the various controllers interact so KISS.

I also note from that thread Sean took power from the sunroof (as I did on my PF) and similarly just found a good earth point.

pete-p · #2 8th July 2021, 03:00 PM

So I've been studying the wiring diagram for the interior lights and think I have the solution.

The usual plug on the mirror with/without dimming has the pins below:

1. Red - Always live even when ignition off.

2. Grey/Green - Switched live with headlights. Also same colour wire provides power to other lights (e.g. ashtray)

3. Green - Unsure. Some reversible ground from lights? Goran indicates this as being activated by driver's reading light switch but then connected it to the negative for the Dashcam.

4. Grey - Not sure but possibly related to headlights or perhaps the other reading light, only other grey I can see is between the headlight switch and the relay in the footwell.

5. Blue - Ground. Another blue on the tiptronic switch is connected to ground (brown) so seems logical this does too.

So I found a 9v battery and connected the positive to pin 2 and negative to pin 5 and the red ambient lights switched on. I think this is where I need to connect pins 2 and 1 from the dimming circuit.

Not sure if I can connect pin 3 from the mirror (linked to reading light switching) to pin 6 of the dimming (normally connected to interior front and reading lights) any thoughts?!

pete-p · #3 9th July 2021, 10:54 AM

The next thing I need to work out is how does the mirror come out and go back in?

Does it just pull down somehow?

MikkiJayne · #4 9th July 2021, 11:27 AM

That's the least fun part of the whole process - it is held in with sprung pins and needs a silly amount of force to get it out. The manual shows an angle to pull it from iirc, and it comes out with quite a pop.

pete-p · #5 9th July 2021, 12:43 PM

Thanks MJ.

That reminded me to check the tech dumps in the D2 forum. It suggests using a screwdriver between the mounting plate and mirror base to lever it out.

pete-p · #6 10th July 2021, 08:39 PM

That was remarkably easy, only a little fiddly putting the new mirror back in.

I'm glad I soldered the wires between the two mirror looms, there really isn't much space and scotchblocks may not have fitted through! I didn't connect anything from the interior lighting so just the power from the ambient lighting in the mirror. All works as expected and I didn't notice the interior lights causing any issues.

I think it makes the interior just that little bit tidier and more modern.