Auto-dimming mirror with 4 wires???

I bought an auto-dimming mirror from Impex, number 3B0 857 511 H, and the unit I received has 4 wires instead of 3. One gray, 1 black, 1 white and 1 green. I was following the instruction in this how-to PDF where only a bk/bl, brown and br/bl wire are mentionned. I identified the following to be corresponding wires:
bk/bl = white
brown = black
br/bl = gray

This leaves the green wire. What is it for???

Also, does anyone know if the red led's can be turned off during the day?

Hey, I installed that mirror too with the help of cevans. And the wiring diagram in that PDF is way off.... We tried what it said and had no luck. So we ended up guessing and checking. In the end we only used 3 wires and couldnt for the life of us figure out what the 4th wire was supposed to do. We would put power to it, but nothing would change.

From what I remember the ground wire is the correct. Then put power each of the other 3 wires until you find the one that turns on the LED's(this also turns on the mirror). You will want to wire switched power up to that wire. Then test the remaining 2 wires by putting power to it to find the one that makes the mirror undim.

If you need more help/info let me know. And if you can figure out what that 4th wire does, defenitely let me know.

Also, you will never notice the red LED's during the day.

Thanks David. I did figure out the 3 wires you are talking about. They are of different color but in the same location as on the PDF. That 4th one still eludes me though. As far as the led's go, I just want to make them last longer, that's why I wanted to turn them off. Anyone else can chime in on the 4th wire???

I tried looking up your part# at Impex, and their search returned nothing. Is it correct in the post?

pepper, its an LED, I would not worry about it too much. The life on those things are insane. And most likely they won't just die. They will deteriorate and their light output will diminish over time.

Oh, if you really do want then off then wire the power to the mirror of the headlight signal on the light switch. That way the mirror will only autodim when the headlights are on. Which should be the only time you need it anyways.

Not a bad idea! But seing your first post, I think I'll be ok with them on. Now, that 4th wire however...

There was some speculation a while back that the fourth wire was to be connected to the interior light circuit, so that when power is applied to it (when a light is turned on), the mirror would know not to dim because the light source is coming from within the car.

I'm not sure if that theory was ever tested though.

Ah! Now I have a mission for this weekend!

Interesting...

Well here's what I found... the 4th wire is powered 12v when the mirror is powered (key on in ignition). What other accessory could it be for? Lito, are you there....

edit.. to add to the problem, when you turn the mirror off by pressing the button and leaving the key on, no voltage goes through the wire. The LED's under the mirror are still on. This means that the wire is meant to power something to be disabled by the mirror on/off switch.

I think it may be for controlling anti-dazzle side mirrors. At one point in time some of our research cross-referenced Audi wiring diagrams that shows the 4th wire going to the side mirrors.

We couldn't find anything that we can use on our cars. Since there are no VW-A4 anti-dazzle side mirrors ever made.

L

That makes so much sense now.

So the 4th wire doesnt turn on and off with the mirror dimming and undimming? Now where can we get a set of the dimming side mirrors?

Self-dimming side mirrors.... pity we can't get any. Thanks Lito. I can now go to sleep...