Electrics: Rear view Mirror Auto Dim not working

[kylespk]

O k I have had a look at the forum and I am aware of the few posts dealing with this issue

My understanding from them is that one can replace the glass by glazing on top of existing glass or by dismantling the mirror assembly. These options are fine and I believe that they are for seriously damaged liquid. I have included photos of my mirror and I don't believe that the liquid in my mirror is gone.

When taking the photos I have found a wire with a little black box (as seen in the photos with my mirror) and my mirror does not have a back cover so my question is:

What is the black wire and what is it do and where does it go?

Why is my mirror always on auto-dim?

Is there anything I can do without a full replacement (I went to a Volvo dealer and they said it will be in excess of £500, and the only recommend a full replacement. They did this without even looking at the car!) ?

[SwissXC90]

That black wire and the object attached to it is a microphone, likely for a handsfreee phone system fitted as an aftermarket solution to your car.

Volvo do not do component level repair of electronics,
They do module repair through replacement of the fault module with a new module - in your case a new mirror.

[kylespk]

Most grateful for the reply.

I can now remove the black piece without any worry.

As for the auto dim Mirror... I don't want to put a piece of glass over what I feel is it working piece of glass. I'm also not keen on replacing the whole system. Is there anything I can do?

[SwissXC90]

Originally Posted by kylespk

Most grateful for the reply.

I can now remove the black piece without any worry.

As for the auto dim Mirror... I don't want to put a piece of glass over what I feel is it working piece of glass. I'm also not keen on replacing the whole system. Is there anything I can do?

Replace it or repair it.

You have decided not to replace it, which leaves repair as the only option.

If the glass has failed you can replace the glass
If the electronics have failed you can repair the electronics IF YOU HAVE THE SKILLS AND TOOLS

The mirror is not only an auto dimming mirror, it is also the receiver for the keyless entry and the tire pressure monitoring system-

it is programmed to your car, so some programming is required.

If you have a working donor of identical part number, you could try to fix your one. Do you have surface mount soldering skills and the necessary microscopes and soldering stations to use? Do you have the circuit diagram, or otherwise skills in reverse engineering the mirror electronics?

If not, your options are pretty much limited to replacing the mirror assembly...

[kylespk]

Originally Posted by SwissXC90

Replace it or repair it.

You have decided not to replace it, which leaves repair as the only option.

If the glass has failed you can replace the glass
If the electronics have failed you can repair the electronics IF YOU HAVE THE SKILLS AND TOOLS

The mirror is not only an auto dimming mirror, it is also the receiver for the keyless entry and the tire pressure monitoring system-

it is programmed to your car, so some programming is required.

If you have a working donor of identical part number, you could try to fix your one. Do you have surface mount soldering skills and the necessary microscopes and soldering stations to use? Do you have the circuit diagram, or otherwise skills in reverse engineering the mirror electronics?

If not, your options are pretty much limited to replacing the mirror assembly...

One cannot argue with such straightforward logic.

I will try and look at the electrics.

Yes i have soldering equipment, circuit diagrams (though I have no electrical knowledge) but I think this might be too big of a push for a simple, cheap full restoration.

My car does have keyless entry (via key fob) but no tyre pressure sensor (that I am aware of).

For me, where the let down is, is the fact that I cannot diagnose whether it is a glass or electric problem.

If it's glass, great then its donor and some disassembly. I was hoping to see if there was a fuse or something simple electrically that I could sort out.

Swiss, thanks for the brutal truth, mate. I will strip it down after the holidays and see what I can figure out.