R129 Rear View Mirror IR led (red one) not working

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Active Member
Feb 13, 2007
R129 SL500 from 96

For quite a few years my red LED has not worked on the rear view mirror (part of the IR sensor that sits underneath it)

I have taken it apart and the led bulb holder looks pretty damaged

I have thought about soldering the wires straight onto the board but decided against it as i think i would make things worse (Jethro Bronner on youtube introduced me to this german word Verschlimmbesserung which applies to me in this case) and like to get it professionally repaired, does anyone know of anyone who can do this?

r129 ir board.jpg

I did purchase a mirror from a W210 eons ago and this board

a) works perfectly fine in my car
b) has non damaged bulb holders and
c) did not come with LED's :-(

but I purchased some 12V bulbs


And tried to fit them but failed miserably, i think the way it is supposed to work is to cut the wires from the bulbs to a shorter length and then by magic you push them into the fitting and if you are a wizard or very experienced at it the tiny little wires at the bottom of the holder which you can barely see (see pink arrows) should touch the wires of the bulb and he presto it works, i have tried this dozens of times but have had no joy

w210 mirror.png

All this work just to get the RED led to work, it has been on my todo list for years and years and like to figure this one out :)
I soldered the led onto the w210 board and both lights work. Green when unlocking and red when locking (and red led does not flash when alarm is on)

I bit the bullet and soldered the led light onto the original r129 board and it works too. Result. however the red led keeps flashing. Just like the door led flashes red. At exactly the same time.

is this expected behaviour? I know the door led is supposed to l flash red every 5 seconds or so but the red mirror led has never worked for me.

any r129 owners who can confirm ?
I went ahead and purchased another w210 mirror in cream / mushroom / beige colour on EBay for £20 with the intention off only using the front cover as mine only had 2 of the 4 tabs broken off so the mirror was rattling.

Despite having the same part number they were a bit different so had to get the dremmel out to cut some plastic to shape and drill 2 square holes :). Also colour is slightly different. Sun will sort that out over the course of next few years. 7B3EEC73-E789-4D5A-86A2-ABCD60D4E2FB.jpeg
All went well and when I put the back cover on 2 other plastic tabs of the rear housing broken off but it still fits together okay (remember German word I used in my first Post)
Anyway all working perfectly now. Red led flashes when you lock the car and it blinks at the same time as the door led.

I may change over the rear cover some day but it also needs modifying and I may break some other brittle plastic so perhaps better to leave it alone

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