Last week i drove my friend's 05 c230 found there is a small Ambient light on the bottom of rear view mirror which light up the interior nicely. However there is no such a light on my 02. So i decide to retrofit a LED into my pre-facelift rearview mirror.

Things needed:
some 5mm amber/yellow LED (i got an 8k mcd amber LED)
Some resistor in order to let LED work on 12 volts power( i use 1/4W 5.6K ohm resistor )
Some wire and electric tape
Dremel tool or hand drill with material removal attachment.

First remove the overhead control unit,Use flat screw driver pry out the plastic cover of ovderhead dome light. Then push two notch together and pull it downward. The overhead unit should be pop right out..use flat head screw driver pry out the microphone( the black part in the center of the mirror stand) now follow the wire find the connector (it hide inside the gray foam )the microphone wiring harness.Disconnect the mirror wiring harness from overhead unit. Remove the rearview mirror


Open the plastic case which hole the mirrot and disconnect the white harness from the mirror IC chip.


I need find out which wire provide +12v power once i turn the key into 1 position.look at the harness carefully. There are two brown wire (ground) two blue wire and pink wire. It's easy to see the top brown wire and bottom blue wire are connected to the home link box which i wondn't touch. The rest 3 wires,Brown is ground what about the red and blue which provide the +12v power? I then connect the harness back to overhead unit to test They both provide +12v once the key turn on. well.i first give the pink wire a try. I hook the led to pink (+12v) and Brown (-) and turn the key on. the LED light right up. However the LED keep blinking... ok i will try the blue(+12v) and brown(-) wire,Yes. The blinking problem goes away.


Now need drill out about 4-4.5mm hole to place the LED.i decided the drill the hole right next to the second clip on base cover. Things will comes easy if you have a dremel with a material removal attachment. Because i didnt get myself a new dremel since it burned out. I just attach the my dremel tools direct to my drill. Because i am going to make a hole on plastic so i dont wanna a high speed drill which will melt the plastic. My hand drill work just prefect. Then i make some 4x4mm mark on the plastic and drill it slowly.



Use some 800 super fine sand paper to do some finish touchConnect the harness to thre overhead unit and test. make sure everything is working.


Reassemble the rear view mirror and overhead unit.


Time for some Beer!

 

Just FYI :i took some pictures with the LED on and off. So you can see what's the different.

With LED off (i use a black tape to cover the light)


LED on



BTW After the rear view mirrow DIY i changed the little bulb in my ciarg light too So now the interior lights are all working.



Another view with LED off



LED on



more pics

 

Wow good job man looks great.. I just might have to do this.. First is the stepper motor links =/

 

wow LOOKS AWesome.. Can you tell me where to buy the LED? and resistor? im interested

 

Weee... somebody actually did it... waiting for this diy... bought the led long time ago but was scared to do it... anyway can I have the pics from the bottom??? wanted to see where and how you put the led... anyway good job...

 

nice job

 

Thanks guys.

This is the bottom view of the mirror. The hole on the mirror cover is about 4.5mm. It was.5mm bigger than what i want. However the base of the LED is 5mm so it will hold the LED fine. I also apply one drop of super glue to the LED base to make it in place tight.






Here you can see the bottom of LED is a little wider (5mm) ,And that's the place where i apply the super glue(one drop only).. It would be nice if you put a LED holder in between the hole and LED,That will fit perfectly without gap.



I got Both LED and resistor at Fry's electronic store. I think you can find them at Radio shack too.



Costs:
LED is 8k mcd amber color $3.78 (a lil expensive than i thought).
Resistor are 5.6k ohm 1/4w 25 pieces $ 1.99
Total cost under $6.00 Overall, not a bad deal.

 

great DIY.

 

that is nice, looks to be very relaxing at night.. ill might have to try that..

 

Hehe. The LED light up the interior really nice at night. It is brighter than my friend's 05 oem light. And the amber ambient light also add some luxury feel while driving at night. Plus it is a cheap diy. Really worth to do it. Just my $0.02

 

So the led will turn on when you turn on the light or turn on when you start engine?

 

The LED will switch on while you turn the key 1 click. and it will stays on till you turn the key to off.

 

nice thanks. Have any pics of the actual wiring with resistor?

 

Looks good.. I've been wanting to do this mod. Just don't have much time these days.

 

I dont have any picture of the actual wiring. But you can view the picture and follow the 3 step instrution below.It is an easy job.
1. you need strip the blue and brown wire at the mirror connector and let the wire exposing the bare copper.
2. Prepare The LED:
in this step you need connect the resistor and LED together.
You can soldering the resistor's lead to LED's + lead. and soldering about inch wire to the other end of resistor. and this wire is going to connect to the blue wire (+12 v) and soldering 1 inch of wire to LED's short lead and this wire is going to connecrt to the brown wire(ground).
Because LEDs can be damaged by heat when soldering. So If you dont feel comfortable at soldering. You might wanna try just twist the wire to the lead follow by electric tape without soldering.
3. Twist the LED's wire and mirror wire together and apply some electric tape on each wire. It's done.

 

Just some added info regarding the LED's in the rear view mirror. e1000's light burnt out awhile back (OEM is an incandescent bulb with a little orange condom slip cover over the bulb), so he made his own (LED). The posting is here:

https://mbworld.org/forums/c-class-w...ew-mirror.html

Nearly the same day his burnt out, mine did as well. I ended up getting the same LED setup from e1000, and replaced my bulb as well. My DIY is further down in e1000's post above. Although my pics were more of an overview of what's inside our rear view mirrors.

We should compare m111power's mirror pics with mine, to see the differences between an 02 and an 05. For starters, my microphones are inside the mirror housing, rather than the black round one m111power has on his. Also, in one of my pics (11th pic down), you can see where the OEM hole is for the light on the 05+ mirrors. It's very close to where you put your m111power, although it's set further back in the housing rather than right at the edge of the plastic housing.

Cintoman

 

Good info. Cintoman and e1000 's post cover the facelift w203 mirror LED project. Looks like 05's light is mount in the middle of the mirror. hmm..i am thinking mount the LED in the middle should be a good idea for some narrow light angle LED to light up center consol evenly.

 

might do this...getting bored and want to do some DIY mods. lol

 

Frank, do mine too?

 

ok i wanna do this so bad. just one question about it. any of the picture thread's i've seen the mirrors were auto diming. my mirror doesn't have this so where do i tap into can anyone tell me

 

Oh...so your mirror actually has a manual lever that angles/dims the mirror? I'd love to see a pic of this, as the vast majority of the US market W203's have the auto-dimming mirror. Even though it's an option, I believe it's part of the sunroof package here in the US, which includes (on the 4-doors) the rear sunshade, auto-dimming mirror, sunroof, and rain sensor. And this sunroof package seems to be on 99.9% of the US cars.

Cintoman

 

a picture of your mirror might be helpful. And do you have home link in your rear view mirror?

 

i'll take a pic. i don't have a sunroof....... i spent ages looking for a purple w203 and the ones i could find didn't have a sunroof, the colour was more important to me. i don't have homelink either never heard of it before whats it for i do have auto wiper though

 

Try to open the case of rear view mirror.and look inside to see if there any wire could supply +12v. If there is no wire inside the mirror case. you might need find some other +12v source on the overhead unit and run it into you mirror.

 

yea was thinking about the supply that lights up the buttons so it would only come on when you turn on the lights don't need it on all the time