Central Locking Switch Light



This is a description of what I did to add this feature on my 1998 BMW M3.  I recommend thinking through what you are doing very carefully before actually doing anything.  Take your time, and double check everything you do.  I won't be held responsible for anyone attempting this on their own.  You cut, drill, bend, burn, melt or break pieces of your car at your own risk.  In some cases, this will PERMANENTLY modify parts of your vehicle, and if you are not careful, you may scratch or mar visible portions of your interior.  You have been warned.

I am also assuming some basic knowledge of wiring and automotive modification.  I don't describe every step in minute detail.  If you don't know how to solder, stop here and get someone to help you.  If you don't know how to remove interior trim pieces, stop now and get someone to help you.

I have written detailed instructions on how to perform this mod on the interior sunroof switch.  I recommend you read that first, since I will assume knowledge of that procedure in the following instructions.  The interior sunroof switch is probably the easiest of the interior switch lights, so if you can't manage that, you should not venture further.


Ok, I wanted a blue interior.  I like blue, plain and simple.  That BMW orange interior is just too blah for me.  I started with the sunroof switch because it was easy to get to, and I figured if I blew something up, that would be the cheapest component to blow up, and the least necessary (Its winter!  No need for sunroof!).  I moved on to the console switches, and have found great difficulty in some of these.  I recommend carefully considering what you are about to do.  There are parts of the car I cannot yet convert to blue, which is going to leave my interior lighting somewhat less than perfect.  I am willing to accept this in order to motivate me to fix it.  Don't blame me if you can't ever do your climate control, or if some things don't match up, whatever.  You have been warned.


I got everything from Radio Shack and http://www.eled.com.  I already had a soldering iron and solder, but both are cheap from Radio Shack.

1 -  3mm, 200 mcd, 3.65 V, 20 mA, 468 nm blue LED

Basically, the stock orange LEDs is  replaced with an LED color of your choice.  This example is blue.  In this example, a 3mm LED is used rather than an SMD, or surface mount LED.  I recommend using this size rather than the surface mount, which would be more difficult to solder, in my opinion.  You are on your own as far as the electrical specs of these components.  I believe the stock ones to be 4 or 5 volts, 20-40 mA, 50-200 mcd, but these are just estimates.  This same LED was used in numerous other locations in my vehicle, fairly well.  This LED is MUCH brighter than the stock LED.  I like the blue, so it doesn't bother me, but it could be distracting to some people.

There are yellow, blue, red, green, white, orange (duh!) LEDs available, and MAYBE even purple LEDs somewhere, I am looking for 3mm.  There are blinking LEDs, multicolored LEDs, lots of possiblities.  Feel free to experiment.


Soldering iron
Wire cutters
Small Flathead screwdriver


Again, please take your time when making any permanent modifications.

Access the central locking switch area by removing the shift boot or shift mechanism cover.  Then you can reach under the center console and push the switch out.  Disconnect the switch from the connector.  You will have this:

Next, remove the outer switch housing by pressing in the metal tabs on either side.

Insert a small screwdriver in the openings marked with red arrows on the bottom of the switch.  There are two tabs that must be pushed outward to disengage the button from the switch.  I have been told that the switch can be forced off without breaking anything, but I broke the tabs.  This can be avoided, but it is tricky.


Remove the button from the switch, remove the two springs, then pry apart the gray switch core from the black switch shell.  In the picture below, the red arrow marks one of the hooks that hold the tabs mentioned in the previous step.  To the far right are two blue circles.  The green scribbles represent the black tabs that I broke, which engage the gray hooks, like the one indicated by the red arrow below. 

In the picture above, it is an unfortunately blurry view of the light and switch assembly, after installing the new LED.  Remove the stock LED by touching the soldering iron to the soldered edges of the SMD LED, and when the solder heats up, push up and away on the LED, to sort of lever it away from the circuit board.  Repeat on other side.  **  Please don't say I didn't tell you to BE CAREFUL!  This will PERMANENTLY modify your vehicle, and restoring the car to its original condition would be difficult.  You don't want to unsolder/cause a short by heating the wrong bits or being jittery, either.  Use a third pair of hands like a vise if you can't be very careful!  A small tip soldering iron helps. 

I didn't capture negative and positive, but you can connect this small circuit board assembly to the connector in the car and test the LED by touching it to the contact points with the lights on.  Be careful, but I never had any problems doing this.   Cut the leads of a new LED to about 1/8".  Keeping track of negative/positive, solder the new LED to the small circuit board assembly where the SMD LED was.  This takes some careful soldering.  Make sure to solder the LED so it is oriented straight up and down.  If the LED is crooked, the light in the switch may not be uniform.  Test it out before putting the switch back together.  Reassembly of the switch is opposite of disassembly.

Ok, now if you managed to get yours apart in one piece, you are golden.  If, on the other hand, you forced it apart in frustration like me, don't despair.  You can purchase a new one from your BMW dealership.  Not sure how much it would be, and its probably a special order item.  But central locking isn't really THAT important, is it? 

Here is how I put my broken one back together.  The springs that are there try to push the switch which is held by the little hooks.  I simply cut the springs about 2/3 and stretched them apart slightly.  I did this a few times to get it right, however it is not quite right actually.  The switch does protrude outward just a tiny bit.  I am ok with this for now, but I will get a new switch one of these days.  I am anal that way.

Good luck!