HELP!!! I have a question for anyone who may know. I have a 06 CLK350 that I recently aquired. I noticed that when it got dark and I reached for the headlight switch I could not tell what posstion it was in. Normally i leave it in the AUTO position but if you need the fog lights you have to turn it clokwise. I assumed a bulb was out. I removed the control module and saw that the knob is back lit by LEDs but the posistion indication part does not have LEDs installed. There are pads on the circuit board but no LEDs. I find it hard to beleived the MB would do such a dumb thing, but that is what I have. Anyone else noticed this? Any solutions? I was thinking about verifing that there was 12V on the pads and soldering in a few LEDs but I was concerned that I may mess somthing else up.

I seem to recall that lighting on the headlight switch was discontinued on all models sometime in the early 2000's. Obviously, this was to same money, but the justification was that most drivers would use the "auto" position and rarely touch the switch.

Be careful if you valet they often turn the light switch ultimate off position........ Which if you are expecting lights to come in automatically and the don't you can be a target for traffic stop..... Which can be bad if you drink at dinner.

If you activate the DRLs (set the "always on" feature for the headlights on the MFD menus), then "off" is the same as "auto".

the circuit is still there, just no LEDs installed. thinking about verifying voltage is there and adding them back. there is room to add a couple standard white LEDs.

I have been reading manuals and digging around the internet to find out why my headlamp position indicator lights never came on just like the originator of this thread. I called a local shop and the local dealership service department and they said they get a phone call a week or people bringing their cars in thinking the LED lamps behind the switch are burned out. Turns out they are only painted onto the lamp switch unit and are not lite from behind. I also have always driven my S550 in the A - auto position and never think twice about it. However, a last week I was driving in the dark and needed to switch the lights to fog lamps, but could not tell what position the switch was in. Pulled the car over on the side of the road and had to turn on the interior lights to see the position of the switch. This simple, basic light is not suppose to light up! The whole interior of the car lights up every bell and whistle, but no light for the biggest safety feature - headlamps!!!!! I am still blown away that a $2 bulb couldnt have been configured into a $150,000 car. I checked and the new 2015 models do not back light either. So, thank you to the person who asked the original question - it lead me to do more searching and I found the answer.

Took car in for service at authorized dealer Autobahn Belmont. I wanted to know why I could not read the headlamp switch illumination after receiving car from valet at night with head lamps off. Technician did not know the answer. All he reported is that there are no codes to check stats of lamps. There is only one bulb in the portion of the switch that the user turns, but no way to see the OFF AUTO etc settings. Service people are not the brightest bulbs in the employ. Now I wonder what else they don't know that is mission critical. Thanks for the thread of enlightenment.

Ah the headlight switch issue again haha:

https://mbworld.org/forums/clk-class...umination.html

04 switch at night