I have changed regular mirror in my Citroen C4 to electrochromatic. That is kind of mirror that turns darker when in night other car driving behind you would flash in your mirror, so you will not be blinded. It has two light sensors – from front and from behind – if light from behind is brighter than from front mirror dims automatically.
I bought such mirror from disassembled Citroen C4 VTR (15 Euro bargain).
Unfortunately I do not have full photo documentation.
There were basically two problems:
a) How to hang it on the window – hanger is totally different
PHOTO: OLD HANGER (IN BACKGROUND NEW MIRROR WITH ALUMINIUM ARM AND PLASTIC COVERS)
I had to de install from the new mirror hanger piece that is mounted by screw and make new piece that would feet slots on the windscreen from old mirror. By myself I cut of piece of metal plate (kind of “v” shaped) and attached it with the screw.
Then back of the new mirror arm had to be saw off – this new mirror had different hanging system – not slight in and out. So I had to adjust it by cutting out around 1cm of back wall of the mirror arm.
To make it look good from outside, as mirror leg is wider then in old mirror. I cut out proper shape from the thick black rubber. So from the outside it looks ok.
PHOTO: NEW ELECTROCHROMATIC REAR MIRROR INSTALLED!
b) Second problem – it requires electricity – how to connect it:
Mirror plug has three pins – power, mass (ground), and control (steering).
You need source of electricity that is switched off when the engine is not running – I used front lighting in the cabin – but not the middle one that can be light up when the engine is off, but lights that are around it – they work only when engine is on. I found there two unused sockets when I took of the lamp:
PHOTO: CHECKING CABLES FROM FRONT LAMP (STILL WITH OLD MIRROR)
I used one of this sockets – they provide power (AC) and ground (mass). As a cable I used CD audio cable (one from CD rom device that used to be attached for direct audio plugging).
Mirror works – it gets darker when it should, and goes bright again when light changes.
So mirror works as it supposed to. But not quite. Still the mirror has control pin not connected – Normally it should go to the computer, or be connected to rear gear. So when you open the door or drive back on rear gear mirror should not go dark. This third pin is in fact way to block dimming in certain situations.
I have connected “control”. Now mirror does not go dark if rear gear is on.
That was quite easy.
I added one cable (I took it from old fixed phone handset cable) and without any issues put it under celling lining with screwdriver (there is plenty of space in there). Removing cover of the left front roof support is not a problem two. Then hole for already existing cable is also big, so you can easily add new one.
Then thanks to the diagram I have located the plug on panel under the steering wheel. This plug have many cables but on mine there were only four unoccupied. With AC sensor I have identified one that was active only when rear gear was on. This one is in fact rear gear signal that I was looking for. I connected control pin in the mirror to it.
PHOTO: GREEN CABLE IS ONE THAT I ADDED
