W203 Mirror problem

[KaraAli]

I've come across a problem recently. The indicator on the drivers' side wing mirror only works when I fold the mirrors (automatically). When i press the button to open them again the passenger side works but my side does not, followed by a malfunction on the computer screen. Anyone know how to solve this?

 

[c270_w203]

Likely broken wires -fixed mine today..

Hi there, I've had exactly those symptoms on mine (a 2003 W203 C270 CDi Avantgarde SE saloon) only on the near side mirror. It's been going on a week or so now so did some research and concluded that it was most likely down to a broken wire (courtesy of the age of the car and continuous use of the folding facility whilst parked up !). Unfortunately it seems to be a common problem according to other posts and worse still, the wiring loom itself doesn't appear to be available as a separate part (although I haven't checked this with the dealership), meaning that ordinarily you're looking at whole new mirror assembly.

However, on the basis the most likely cause is a broken wire that could be replaced with care, I set about doing exactly that today and it has worked - I now have a fully functioning indicator again and I didn't find it too difficult a task if you're OK with a bit of disassembly work, are a dab hand at soldering and have Torx screwdriver bits..




The procedure for my age of car (yours may be different if it is pre mid 2002) is roughly :

• With the mirror folded in, remove the exterior mirror housing (carefully prising away the internal clip with a screwdriver)
• Remove the interior door handle, triangular tweeter speaker assembly, door lock trim piece and lastly, the door lining (this is all to expose the 2 mirror connectors which sit inside the inner door shell).
• Remove the 2 plugs from the 2 connectors and remove the 3 exterior bolts holding the mirror housing to the bodywork and remove the mirror assembly from the car.
• The 2 wires in question are the ones in a black / red housing that mate with the LED unit on the indicator housing. One wire is brown / black and the other is black / white as I recall. Both run back to the right hand connector you've disconnected. As it's difficult to determine which of the 2 (or unluckily, both !) wires may be at fault, I bridged them both. I used a piece of equivalent thickness, multi-stranded copper wire and soldered each in place appx 1cm from the respective ends of the existing cable (assuming the break was somewhere in between). Lots of insulation tape applied to the joints, which I sodlered slightly off-set to each other just to avoid any possible contact.
• The only difficulty is how to route the new wires (before soldering !)through the rubber weather seal as the grommet has no gaps. I chose to route it through an adjacent hole which mates up to an otherwise useless looking plastic nodule..
• I partially re-assembled everything prior to bolting it all back in place to make sure all was well and voila ! job's a good 'un ..

Hope this helps, let me know if you need any further guidance and I'll do my best to help.... the alternative does look to be a fairly expensive mirror assembly replacement unfortunately.

All told, about 3 hours work, but I am quite methodical and didn't want to mess up other stuff into the bargain

 

[nigel cross]

Well done, perhaps this should be moved to the How to section