[Muaijaz]

Hey all,

I just finished installing an auto-dimming mirror and it works! I followed the guide on the GLA Forums website, but I figured I should put it here as well. All you need is an auto-dimming mirror and the wiring harness. I found the mirror on ebay from a totaled CLA and the harness at Pelican Parts, Part#156-540-56-05-MBZ . Here are some pictures of it! I'll post a bit later with pictures from tonight, as well as the actual guide on how to do this.

 

[SunsetCLA]

I already have it, but I love when people make dyi guides. Great job!

 

[jmc]

Good show! Surprised no computer gadgetry needed? Cuz there are activation voltages etc associated with the dimming system ...

 

[Muaijaz]

Tools needed: Paper Clip, Adjustable Wrench, Butter Knife and fork (I didn't have a trim removal tool), Credit Card (Again, no trim removal tool)

Step 1: Buy parts
Step 2: On the wiring harness, remove the pins from the connector. It's a 2 step process. This is where you will use paperclips. First, push the pin down from the face. This should allow the pin to come halfway out. Then push the pin down from the center. This will allow the entire wire to come out of the connector.

Step 3: Disassemble the N90 overhead unit and the rain sensor cover. I took the wires out, but I'm not sure if that's completely necessary. You will need a the credit card here. Push the card into the trim, push the unit forward, and then it will just fall out. You might have to pry it down, but I got lucky here. The rain sensor cover comes off just by pulling it down. If your SOS buttons are stuck, there are 2 fasteners on each side of the buttons. I used a fork here to separate the clips. Oh, my rain sensor cover also has my hardwire for my Radar. You won't have this. Once you're done, you should have something that looks like this:

Step 4: Remove the mirror. You will need the wrench for this part. The back part of the mirror has a groove for the wrench to turn. This is about 3/4 of an inch. The smaller one won't work. You're gonna rotate the wrench to your right if you're facing the mirror (towards the passenger side). The mirror itself will end up facing left. I did this after wiring the harness, but this process definitely would have been easier if I did it before.

Step 5: Once you have the mirror removed, thread the harness through the gap between the N90 overhead unit and the rain sensor area. Once you have done this, the blue connector side should be hanging.

Step 6: On the right side of the N90 unit, there is a white connector already plugged in. You will need to pin the pins from the harness into this one. Here is the diagram of how I did it:

Step 7: Plugin the mirror wires. The wire from your original mirror has a white connector and will connect to the white connector on your new mirror. The harness will have a blue connector and that connects to the blue connector on your mirror. (Shocking!)

Step 8: Test everything out. I didn't do this part, but it would make sense to test everything here once all of the wires are plugged in.

Step 9: Do everything above in reverse to get your mirror installed.

Step 10: Enjoy your new mirror!

Idk if y'all had this issue, but on my old mirror, the lights from cars behind me would reflect off the N90 overhead control unit (Where your sunglasses go) into the mirror and made driving at night more annoying. This solved the problem for me.

Here are a couple of pictures showing the difference. The first picture is one without a car behind me. The second shows the mirror getting bluer to reduce light:

P.S. My compass was stuck on SW when I did this. There is a small hole near the left light at the bottom of the mirror. Take a paper clip and push that button to reset the mirror. I had to drive in a circle to re-calibrate the compass. Everything is working flawlessly. I hope this guide helps! Good luck and have fun!

 

[Muaijaz]

Good show! Surprised no computer gadgetry needed? Cuz there are activation voltages etc associated with the dimming system ...

Well, I guess I'm gonna find that out tonight haha. What needs to be done to enable that? Also at the very least, I have a garage door opener and compass now. It cost me a total of $130 including shipping for both the mirror and the harness. I also plan on getting some of that back selling my original mirror, so it's not the worst way to spend $75 hahaha

 

[Muaijaz]

Good show! Surprised no computer gadgetry needed? Cuz there are activation voltages etc associated with the dimming system ...

I just went out and tested it this evening. Everything is working great! My compass wasn't changing directions initially, but a couple of resets did the trick. Very satisfied with this whole thing . Maybe it's because I bought the mirror used and it was already activated. Idk, I'm happy haha. Check out these pictures of it dimming!

 

[jmc]

Good for you! Its frustrating most of the time when one tries diy upgrades and bumps into silly obstacles like need for computer coding
Yours fortunately seems to be a localized system that just draws power to activate and is based on ambient conditions
Very cool project!!

 

[dre_andrei]

Many thanks for the detailed instructions.
Would you also be able to share the link to the original GLA Forum post which helped you?

Thanks,
Andrei

 

[Muaijaz]

Many thanks for the detailed instructions.
Would you also be able to share the link to the original GLA Forum post which helped you?

Thanks,
Andrei

I can't remember where I found it or find the link to the original post. This process works for the GLA in the exact same way if you wanted to upgrade that mirror.

 

[shmitty]

Thank you for all the information that you posted, I was just wondering if you show how you used the fork to remove the info /emergency buttons form the rain sensor cover.

 

[Zig]

Step 2: On the wiring harness, remove the pins from the connector. It's a 2 step process. This is where you will use paperclips. First, push the pin down from the face. This should allow the pin to come halfway out. Then push the pin down from the center. This will allow the entire wire to come out of the connector.
View attachment 64882
------------------------------------------------------------------------------------------------------------
A little add-on to the process...

I did the installation and found that it is easier to "pop" the locking tabs to remove and insert pins and then re-lock the tabs. I used tip of a knife to open the locking tabs....

Attached below is the connector from the new wiring harness with popped locking plates to help you visualize.

 

[stuntdancer]

Tools needed: Paper Clip, Adjustable Wrench, Butter Knife and fork (I didn't have a trim removal tool), Credit Card (Again, no trim removal tool)

Step 1: Buy parts
Step 2: On the wiring harness, remove the pins from the connector. It's a 2 step process. This is where you will use paperclips. First, push the pin down from the face. This should allow the pin to come halfway out. Then push the pin down from the center. This will allow the entire wire to come out of the connector.
View attachment 64882

Step 3: Disassemble the N90 overhead unit and the rain sensor cover. I took the wires out, but I'm not sure if that's completely necessary. You will need a the credit card here. Push the card into the trim, push the unit forward, and then it will just fall out. You might have to pry it down, but I got lucky here. The rain sensor cover comes off just by pulling it down. If your SOS buttons are stuck, there are 2 fasteners on each side of the buttons. I used a fork here to separate the clips. Oh, my rain sensor cover also has my hardwire for my Radar. You won't have this. Once you're done, you should have something that looks like this:
View attachment 64883

Step 4: Remove the mirror. You will need the wrench for this part. The back part of the mirror has a groove for the wrench to turn. This is about 3/4 of an inch. The smaller one won't work. You're gonna rotate the wrench to your right if you're facing the mirror (towards the passenger side). The mirror itself will end up facing left. I did this after wiring the harness, but this process definitely would have been easier if I did it before.
View attachment 64884

Step 5: Once you have the mirror removed, thread the harness through the gap between the N90 overhead unit and the rain sensor area. Once you have done this, the blue connector side should be hanging.
View attachment 64886 View attachment 64885

Step 6: On the right side of the N90 unit, there is a white connector already plugged in. You will need to pin the pins from the harness into this one. Here is the diagram of how I did it:
View attachment 64887

Step 7: Plugin the mirror wires. The wire from your original mirror has a white connector and will connect to the white connector on your new mirror. The harness will have a blue connector and that connects to the blue connector on your mirror. (Shocking!)

Step 8: Test everything out. I didn't do this part, but it would make sense to test everything here once all of the wires are plugged in.

Step 9: Do everything above in reverse to get your mirror installed.

Step 10: Enjoy your new mirror!
View attachment 64888 View attachment 64889



Idk if y'all had this issue, but on my old mirror, the lights from cars behind me would reflect off the N90 overhead control unit (Where your sunglasses go) into the mirror and made driving at night more annoying. This solved the problem for me.

Here are a couple of pictures showing the difference. The first picture is one without a car behind me. The second shows the mirror getting bluer to reduce light:
View attachment 64891 View attachment 64890

P.S. My compass was stuck on SW when I did this. There is a small hole near the left light at the bottom of the mirror. Take a paper clip and push that button to reset the mirror. I had to drive in a circle to re-calibrate the compass. Everything is working flawlessly. I hope this guide helps! Good luck and have fun!

Hey all,

I just finished installing an auto-dimming mirror and it works! I followed the guide on the GLA Forums website, but I figured I should put it here as well. All you need is an auto-dimming mirror and the wiring harness. I found the mirror on ebay from a totaled CLA and the harness at Pelican Parts, Part#156-540-56-05-MBZ . Here are some pictures of it! I'll post a bit later with pictures from tonight, as well as the actual guide on how to do this.

Thank you for sharing this. I have the 2016 base model and was able to buy an auto dimming mirrors on eBay. I installed it right away but there was no blue connector on my car. Based in your recommendation I was able yo buy the wiring harness and installed it this morning. Everything seems to work and was able to reset the compass and program my 2 garage door opener. No luck with our subdivision gate though. I will test if the dimmer will work tonight.

Oh btw, the top center panel can be unlatched using a credit card.

 

[stuntdancer]

After install with working compass.

Position of credit card insertion to unlatch.

 

[Stefano]

Thanks for your guide. I have a question. I can't find the harness.
Is there any way to know which wire is the ground and which the +12 on the mirror? I have a
multimeter.

I did it, brown is ground and yellow +12

 

[jmc]

i have not yanked that overhead out yet ... though i know the germans ... + and - are not red and black
consider yanking it out keep everything plugged (so no silly codes or dash christmas lights) and poke the connector points from the wire side with the mm

 

[hickmic]

Thanks for your guide. I have a question. I can't find the harness.
Is there any way to know which wire is the ground and which the +12 on the mirror? I have a
multimeter.

I did it, brown is ground and yellow +12

And for what purpose/voltage? is the third green wire on the mirror used?

 

[hickmic]

And for what purpose/voltage? is the third (red/blue) wire used?

 

[aap99]

Hi there - thank you so much for the guide. I have a 2017 mercedes B250 and am trying to do the same thing with my car as it didn't come with the autodimming mirror or Garage door opener. I purchased the mirror from a salvage B250 and wanted to check if the wiring harness with Part#156-540-56-05-MBZ would fit a B250. I am pasting the photos of the blue connector from the new mirror as below. Your help is highly appreciated. Thanks!

 

[mav238]

Hi there - thank you so much for the guide. I have a 2017 mercedes B250 and am trying to do the same thing with my car as it didn't come with the autodimming mirror or Garage door opener. I purchased the mirror from a salvage B250 and wanted to check if the wiring harness with Part#156-540-56-05-MBZ would fit a B250. I am pasting the photos of the blue connector from the new mirror as below. Your help is highly appreciated. Thanks! View attachment 69033

Do you not know the year of the salvage B250? If it's 2013 or later, then it should be good to go.

 

[aap99]

Do you not know the year of the salvage B250? If it's 2013 or later, then it should be good to go.

The salvage b250 was 2015 version..does that mean Part#156-540-56-05-MBZ would fit my 2017 B250 ?