Remove/Replace electrically operated self closing Mirror Complete W169 Carry out repair to self closing mechanism
Should you have the misfortune to have to replace a damaged or defective mirror its important that you ensure it is the correct mirror/component for your car is purchased as there are many many variations
It is also worth assessing the damage to the mirror completer unit as many of the parts are available as separate items and although pricey are a lot cheaper than buying a complete unit.
My auto closing drivers mirror decided that it wouldn't fully open of fully close.
I could have opted to purchase a complete second hand mirror with the colour coded cover to suit my car BUT it wasn't cheap at £300 plus carriage
I could have purchased just the basic mirror body which would have cured the problem but would still have had to strip the mirror and basic parts off mine for the new body.
Fitting the mirror initially looked to be a problem and there is little information available
It require the removal of two plastic components
One that is situated on the inside of the 'A' post which is held in place by two reusable clips
The second is not conspicuous and appears to be part of the door card.
However using a fine small bladed screw driver it can be eased carefully out of it housed position and is held in place by four clips attached to the panel( Removing plastic components is best done in warm conditions clips etc are less likely to snap off ).
Once this is removed the light Brown plug to which nine black wires go is obvious and is connected into the drivers door module and not the mirror /windows switch housed in the door card as one would expect.
REMEMBER YOUR CAR MAY BE DIFFERENT AND THEREFORE USE THE VIN CODE TO ENSURE YOU GET THE CORRECT PARTS FOR YOUR INDIVIDUAL CAR THE NUMBER OF WIRES FOR INSTANCE MAY DIFFER FROM THAT SHOWN.
unplug the light brown connector and attach a length of string to the black wires, the can then be used to pull the plug on the replacement mirror into position in side the door
The remove the existing mirror Remove the three Torx screws located on the inside of the door Steady the mirror as you release the third screw.
With draw the mirror and cables carefully from the door, Remove your draw cord from the used mirror.
attach you pull cord to the new plug and cables and slowly pull it through and into the car and the same time positioning the replacement mirror into its housing .
Replace the three Torx T20 securing screws
fit the light brown plug into the control unit.
With the key in the ignition position two you should be able th test the mirror /window/and indicators for correct operation.
If all is satisfactory replace the two plastic panels as found.
Now if you have the same problem as me in that the mirror will not lock open and not fully close the question is why?
Well I've been able to examine my defective one for the fault and I can tell you that all it was is a pin approx 3/8" inch long 3'16 in Dial that engages with the geared wheel/toothed wheel There is a hole corresponding to the size of the pin and it is that pin that had dropped enough to disengage from the toothed gear wheel hence no drive on the auto opening/closing mirror.
The fault was caused almost certainly by wear in the pin
Having pushed the pin back up into the toothed wheel with a large flat bladed screwdriver the mirror operates 100%
This fault only came to light as a result of my breaking a thin plastic which exposed the gear wheel and dropped pin. The is removable with care but take care it cannot be replaced as a spare part it comes as part of the main body.
Should you suffer the same problem.
1. Fold the mirrors in (Closed)
2. Carefully remove the plastic shield as it is not available as a sperate part from MB parts
3. Check the location of the pin which should be level with the top of the geared wheel (This photo is of the Near side with the shield removed.)
4. If the pin has dropped Lever it back up from the bottom ensuring it lines up with the hole in the toothed wheel, position the pin level with the top of the toothed wheel and apply adhesive to the bottom of the pin to prevent it happening again.
5. If the problem reoccurs it may be necessary to fit a new pin but this would have to be a DIY job as the pin comes with the main body of the mirror at which would cost approx £200.00 with the 20% Vat (January 2020 )
Fitting the mirror initially looked to be a problem and there is little information available 
