C5 X7 interior rear view mirror compatibility

[vodnasol]

Hi all,
My rear view mirror has pretty bad scratches, so I decided to buy another one. Today it arrived and I checked the part number and it is for a C5 with exterior electrochromic mirrors (8153TW), but mine car doesn't have them(8153VT). Can I use it on mine?

[GiveMeABreak]

It's not designed for vehicles without the wiring for the mirror which uses a 6 pin connection and has a different mount too.

[vodnasol]

Both are the same shape and use the 6 pin connector. I removed the old one and noticed it only uses 3 pins and the new one uses 5 pins. The connector from the rain/sunlight sensor has also 5 wires. Is it possible that my car has exterior electrochromic mirrors or they used the same wiring for all cars?

[GiveMeABreak]

Ok, some confusion with what you originally had, but I've now checked on your VIN and can see that you do not have electrochrome rear view mirrors on the doors.

There are different versions of the internal rear view mirror (on the ceiling) and that is why. Your car originally has 8153VT which is the version without electrochrome door mirrors.

8153TW is the version with.

[vodnasol]

Can I cut the extra two wires and use it that way?

[GiveMeABreak]

Which would you cut though? They all have a purpose apart from (3):

Channel Number	Designation
1	+ ignition on
2	Earth
3	Not connected
4	Exterior electrochromatic rear view mirror supply output
5	Exterior electrochromatic rear view mirror earth output
6	Reverse gear signal input

[vodnasol]

I don't have exterior electrochromic mirrors so 4 and 5.

[vodnasol]

So I looked at the wiring diagram for the exterior electrochromic mirrors and the signal from the interior mirror goes straight to them so I can just cut the two wires.

[GiveMeABreak]

Good Luck!

[Hell Razor5543]

Before you cut any wires make sure the mirror and cable will plug in.

[vodnasol]

It worked!

I read how an electrochromatic mirror works, because I wasn't sure if there is any current regulation on pin 4, but there isn't. It just outputs a variable voltage depending on the output from the glare sensor.

[GiveMeABreak]

Well done.