MB C350 CDi Modification Started (LED DRL's 1st)
So I also decided to post about my MB. See below more info about my car:
https://mbworld.org/forums/new-membe...kend-ride.html
While browsing the internet, these forums and some inspiration from my other VW ride.... I decided to start with modifications, nothing major, to the W204 to make it a little nicer but still keep the OEM look and feel going.
I started with the following cosmetic modifications:
LED DRL's: [Front View(s)]
I have the pre-facelift model with the sport package bumper. This means I still have the round fog lights. I found the following from e-bay that is a direct swop while still keeping the original fogs:
LED Tagfahrlicht Mit Gitter DRL TFL Mercedes C Klasse AMG Sportpaket W204 S204 | eBay
So here is the installation complete:


It came out really nice as seen from the pictures. It really looks like it is OEM and suits the car well. I was impressed with the quality of the product right from opening the package. The colour of the LEd's are really nice, I think it is 6000K. These are now much more expense then when I bought them a few months ago. I really wanted the quality from Europe and not China. Maybe they were made in China in any case who knows

As I like to do a decent job and make the wiring look atleast somewhat neat and OEM, I did the following below in the engine bay with corrugated cable sleeves:
LED DRL's: [Engine Bay Wiring]
Ground Cable Route & Connection

Engine Fuse Box Cable Route & Connection for 12VDC

Left & Right Cable Route & Connection under the aircon pipes & front boost pipe


So I got the LED's working with Ignition ON, they are @ 100% Brightness. The LED's do come with a controller box that can dim the LED's to 50% when the headlights are switched on but this is where I need some assistance from you forum members if possible. Below is the driver's side (RHD) headlight plug:

Now from the wires, I understand yellow is the headlight or not? I am not sure if black/blue is the park light or not? I go the plug unplugged and used the wire from the LED controller on the different pins to see when the LED dim but I think I have done something wrong because if looks like all the plugs have voltage to them even if the switch is ON or off for the headlights. Maybe this has to with closing the loop somehow? Can anyone comment on this?
I have tried to see if I can maybe wedge the wire from the LED controller in the back of the plug but there is no way possible. I am a little skeptical about splicing into the original wires of the car and would rather opt for wiring into the fuse box and get the voltage from there. Is there a specific fuse # for the park lights? I checked my fuse diagram but maybe I miss something

If all else fails, I will only have full brightness all the time
which is not bad either 
Thank you for reading my post. I look forward to any feedback and assistance
Last edited by Morné Pieters; Jul 16, 2017 at 12:42 PM.


Last edited by Morné Pieters; Aug 16, 2016 at 02:30 AM.
The LED lights up great with the ignition @100% brightness. Now to get the module working, I connected the brown wire with the blue wire. This will give me 50% dim when signal is connected to the extension blue wire on the headlights. Then I took the extension blue wire and connected this on the yellow wire from the headlight plug but here is where the strange part comes in...
The LED's dim and go bright again, dim and go bright again for about 5 times and then just stays bright. I tried it with both engine running and not running.
I am really puzzled by this. I tried different combinations with the blue wire extension like the white wire. The same effect happens. The LED shut off and come back on for 5 times. It is almost as if the +12VDC is not constant but pulsed. Can this be true?
Can someone shed some light on this if I am on the right track or missing something seriously here?
I look forward to any feedback and assistance
Last edited by Morné Pieters; Jul 16, 2017 at 12:45 PM.
I think that the 12VDC are not a constant current but actually pulsed due to the factory DRL option of the halogen bulbs and this messes the signal to the newly installed DRL Module I think....
Maybe I can smooth this out with a cap. I will give it a try
Last edited by Morné Pieters; Aug 16, 2016 at 02:32 AM.

I used a black and red wire to distinguish what the correct polarity would be always. All my soldered connections, I first heat shrink wrapped and after used some insulation tape to tape up the connections. I must actually used some cloth tape over this to give it some more protection but anyway... Some pictures below of the capacitors used and the outcome of the install:
- Home Made Capacitors in Parallel to Smooth 12VDC signal for DRL Controller Brightness Dim

- LED DRL 100% Brightness



- LED DRL 50% Brightness (Dim with low beam switched on)

Last edited by Morné Pieters; Jul 16, 2017 at 12:45 PM.


