W169 rewire wing mirrors - has anyone actually done it?

xxredmaxx

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A150 2007 with electric folding mirrors.

I've just wasted £25.00 buying a new offside indicator element because I got the fault message. Changed it over in 20 mins and all good. Next day I get the same fault message. I can only guess its because they folded away upon locking so must be a wiring degradation issue.

Both mirrors have issues:

Driver's side: Folds away ok. Mirror lens only moves up and down but not in or out. If folded then indicator goes into fault mode.
Passenger side: Does not fold away. Mirror moves in all directions ok

I know I can just drive the car and not bother worrying about if they fold away but these things really bug me.

I can see its fairly easy to remove the whole mirror assembly from the car and unplug from the joiner box.

So has anyone successfully removed the mirror and rewired or repaired existing wires? I have looked around and found comments saying its impossible to remove the cables from the termination plug because they are so small gauge and you need the bullet connectors which are not available as spares. The termination plug is not available either afaik too.

If I find breaks do I then have to solder to repair?
I'd rather replace all 7 or 11 cables.

If anyone can provide me with a walk through from after mirror assembly removal I would be grateful.

I found complete pair of replacements (folding electric) from a breakers at £200 for the pair which is more than I want to spend on a 13yr old car tbh.
 

LostKiwi

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Wire breaks are a common problem if auto fold is enabled.
Easiest way to repair is identify broken wires and run new ones. Cut old wire 1" from each end, solder in new piece and seal with heat shrink plastic.
 
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xxredmaxx

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Wire breaks are a common problem if auto fold is enabled.
Easiest way to repair is identify broken wires and run new ones. Cut old wire 1" from each end, solder in new piece and seal with heat shrink plastic.
Thanks for the help.

Do you have any suggestions where the likely places a wire break will occur please? I took off the rear cover when changing the indicator and to be honest there wasn't much wiring exposed. I'm just wondering how you see the cables if they are hidden inside the assembly itself even if I remove it.

Cheers
 

ZZZZ

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As LostKiwi said, it's a common problem (the question still remains, why exactly am I retrofitting this option to my car, but that's beside the point ;)).

No need to replace the pins, which are indeed tiny - just follow each wire (either 9 or 11, depending on other option on top of 500 - memory folding), and repair. Do this one at a time, as they all black.

These files should help :)
Someone asked me before to decipher the pinout, so I added notes on 245 diagram - same pins on 169, if I remember correctly (the memory group U145 might be different).
 

Attachments

  • W169 Remove_install outside mirror trim up to 2008.pdf
    107.8 KB · Views: 143
  • 169 Power window (PW), block diagram.pdf
    66.3 KB · Views: 127
  • 169 Wiring diagram for right front door control unit (DCU).pdf
    100.5 KB · Views: 165
  • 169 Wiring diagram for left front door control unit (DCU).pdf
    99.3 KB · Views: 158
  • 245 Wiring diagram of outside mirrors - Right.pdf
    54.7 KB · Views: 170
  • W169 Remove_install glass adjustment drive.pdf
    48.4 KB · Views: 106
  • W169 Remove_install mirror lens.pdf
    143.9 KB · Views: 120
  • W169 Remove_install mirror triangle cover on front door.pdf
    69.6 KB · Views: 130
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xxredmaxx

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As LostKiwi said, it's a common problem (the question still remains, why exactly am I retrofitting this option to my car, but that's beside the point ;)).

No need to replace the pins, which are indeed tiny - just follow each wire (either 9 or 11, depending on other option on top of 500 - memory folding), and repair. Do this one at a time, as they all black.

These files should help :)
Someone asked me before to decipher the pinout, so I added notes on 245 diagram - same pins on 169, if I remember correctly (the memory group U145 might be different).
Thanks GLK once again. Youve actualy partially answered another question I had - How many wires should there be for the mirror? I do not have memory options so afaik I should have indicators, (hazard) heating, mirror 4 way control and folding. Is that a 7 wire set?
Also... are there the same number of wires for drivers side as passenger?

The reason I ask is that even though I will try the repair route but as a fall back I have seen some complete units on ebay but I need to know the exact number of wires before buying.

cheers as always for the advice.
 

ZZZZ

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No worries :)

You will have 9 wires (option 500 power folding, but no memory) - see the 245 diagram, it's got every wire identified by the pin number on the plug - you can easily get to the door control module and take a close-up pic of the plug / socket, to see numbers.

Yes, same number of wires for both sides.

There's no guarantee a used unit from eBay won't have damaged wires, or how long it will last before developing the same fault - repairing is probably the best option? Just put a few wraps of Tesa tape or a self-amalgamating silicone one (or both, if enough space).
 
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xxredmaxx

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No worries :)

You will have 9 wires (option 500 power folding, but no memory) - see the 245 diagram, it's got every wire identified by the pin number on the plug - you can easily get to the door control module and take a close-up pic of the plug / socket, to see numbers.

Yes, same number of wires for both sides.

There's no guarantee a used unit from eBay won't have damaged wires, or how long it will last before developing the same fault - repairing is probably the best option? Just put a few wraps of Tesa tape or a self-amalgamating silicone one (or both, if enough space).
Yes I agree and thought the same about ebay purchase. I am attaching the passenger side to day and will see how it goes.
Thanks for confirming 9 wires. Yes I can now see on diagram M21 group and indicator set = 9
 
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xxredmaxx

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well... I have solved why the nearside mirror does not fold.
It must have been replaced by a previous owner and only has 7 wires so not folding type.

Now taking apart the drivers side which does have 9 wires.
 

ZZZZ

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Ah, interesting - didn't think of that possibility ... some people do get very creative with their repairs LOL
At least you can buy a single power folding mirror, and not worry too much about its cosmetic state, indicator lens cracks, etc so might get a bargain.
 
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xxredmaxx

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struck out with drivers side. Could not see any obvious breaks in the cables anywhere. Stripped all old self amalgamating tape but nothing. Back to drawing board.
 

Blobcat

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struck out with drivers side. Could not see any obvious breaks in the cables anywhere. Stripped all old self amalgamating tape but nothing. Back to drawing board.
The breaks will be hidden by the insulation (it will just be the copper inside that's broken) - with careful wiggling you might be able to identify the break through the insulation. Alternatively just cut them back one at a time and replace the bit that moves when the mirror folds.
 

Smudge700

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As LostKiwi said, it's a common problem (the question still remains, why exactly am I retrofitting this option to my car, but that's beside the point ;)).

No need to replace the pins, which are indeed tiny - just follow each wire (either 9 or 11, depending on other option on top of 500 - memory folding), and repair. Do this one at a time, as they all black.

These files should help :)
Someone asked me before to decipher the pinout, so I added notes on 245 diagram - same pins on 169, if I remember correctly (the memory group U145 might be different).
Hi guys. First question here! Do you know what wire to purchase for a rewire? Thanks
 

Tony Dyson

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I would use Tri-Rated cable, a flexible core for the folding operation and will perform from sub-zero to 105 deg C, oil/acid resistant also known as equipment or panel wiring wire. 0.5mm² is rated at around 11A you should be able to buy short lengths from Ebay and amazon
 

Smudge700

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I would use Tri-Rated cable, a flexible core for the folding operation and will perform from sub-zero to 105 deg C, oil/acid resistant also known as equipment or panel wiring wire. 0.5mm² is rated at around 11A you should be able to buy short lengths from Ebay and amazon
Thanks Tony, you are a star! Last question, I have dismantled the mirror as far as I can but cannot access the wiring loom. There must be a way of opening up the mirror to access it. Any ideas pleeeeeease!
 

Exp21

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Hi everyone. Similar issue. On my w245 restyling while I'm driving the folding motor reactivates randomly for a second or so, trying to open the already opened (unfolded) mirror.
What could be the problem? Thank you for help
 
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