CL/W203 dimming rearview mirror -?whats the spare lead for ??

[Smatt]

Hi, I have picked up a dimming rear view mirror for my CL203. I have installed it and the dimming is working great- tested on the roads at night
However, it has 2 leads, but there was only one compatible space in the overhead control panel. There is one more free space, but for a slightly smaller rectangular plug. It appears to work fine without this other lead being plugged in.
The spare lead has a relatively wider white plug on it.
There are no garage door opener buttons on it & it does not appear to have a microphone on it, although it does have a tiny ambience led on the underside which is working. There is a tiny oval(I presume the light sensor) on the centre top of the mirror and an opaque white window on the front side of the mirror body.
Does anyone have any ideas what the spare lead is for??
Many thanks.

 

[miro]

Appears to be from a W208 or W210.

In a diagnostic session it will probably give some trivial error code.

 

[Smatt]

Thanks, Miro. Any ideas whether this other lead would give any more fancy functions?
Currently the cluster is not reporting any errors.
Thanks again for your wisdom,
Matt

 

[alibally]

Has the mirror a mic for a telephone on it . It may be for that.

 

[Smatt]

Has the mirror a mic for a telephone on it . It may be for that.

-No

& it does not appear to have a microphone on it

 

[miro]

Thanks, Miro. Any ideas whether this other lead would give any more fancy functions?
Currently the cluster is not reporting any errors.
Thanks again for your wisdom,
Matt

Either it works or it does not.

 

[Smatt]

Either it works or it does not.

It works fine & I am very happy with that. I was just wondering what the extra wires were for... whether they would give me an extra 100bhp or multiscreen tv or something...
I will shut up
Thanks

 

[Smatt]

Update:
The person who sold this rvm to me thinks the extra lead is to link to dimming door mirrors, ie the rvm controls dimming of the door mirrors, which seems logical

 

[gbjeppm]

Yep that would make sense, my wing mirrors dim, when the rvm does.

 

[miro]

Update:
The person who sold this rvm to me thinks the extra lead is to link to dimming door mirrors, ie the rvm controls dimming of the door mirrors, which seems logical

In the car it came out of that is what the extra wires do.

 

[Smatt]

In the car it came out of that is what the extra wires do.

So if I do want to fit dimming mirrors (along with folding, new door modules, memory frames & 2005 SAM; dependent on finding the parts...) in my(2003 cl203) car, which I had been considering, will I then need to fit a different r/v mirror, or will this one be adaptable?
Thanks Miro