headlight conversion
Thread Starter
Newbie
Joined: Sep 2025
Posts: 1
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s550 gl 550 e 350
headlight conversion
hey guys i brought 2 headlights from ebay that are from a 2010 s550 to put on my 2007 you know the typical upgrade but i didnt know the 2010 has only one wiring plug on the back of the light compared to the 2007 that has 2 lights now i know all the conversion kits people by has the new 2 into 1 wirw so they work but if you just buy the lights seperatly like i did it dont so the question is either where can i buy or get this wire or is there any special way to hook this up as it is ive looked at ever site that i know of the past week and cant figure it out ty in advance for any help
Super Member
Joined: Jun 2025
Posts: 784
Likes: 248
From: USA
You need a specific adapter harness. The 2010 lights use a different system (Xenon vs. possibly Bi-Xenon or different control modules). You can't just wire it directly.
Search for "W221 headlight retrofit harness" or "S550 headlight adapter 2007 to 2010" online. Companies like CARiD, VLEDs, or even specialty Mercedes shops sometimes sell them. Without that harness, the lights won't function properly.
Search for "W221 headlight retrofit harness" or "S550 headlight adapter 2007 to 2010" online. Companies like CARiD, VLEDs, or even specialty Mercedes shops sometimes sell them. Without that harness, the lights won't function properly.
