I just installed the facelifted taillights on my 2003, I too ran into lots of trouble with some parts not lighting up on one or both sides. I ended up reinstalling my old lights, verifying what was supposed to be lit and at what intensity, and then swapping all the bulbs and sockets from the old to the new.

But I still couldn't get both taillights to illuminate properly. I inspected everything, didn't look terrible, and then compared side by side the new to the old. That's when I found very minute corrosion on the new lights' circuit board right where the bulb socket comes into contact with it. So I sanded both the board and the metal contacts on the socket itself and reinstalled. Everything seems to be OK now.

The taillamps (the upper part below the signal) are double-fillament and come on when your lights are on. The brake lights (bottom part) are single fillament and come on not only when your lights are on, but grow in intensity if the brake is depressed.

At least in my situation, only one filament burns in the taillamp section whenever the lights are on, I can't get the second filament to ignite. When the lights are on, the brakelight section is on as well, but is brighter when the brakes are depressed. I'm not sure if this is right or not, but at least I'm not getting any "check brake lights, check tail lamps" messages.

You just have to find a combination of bulbs and sockets with minimal corrosion, and sand down the board on the assembly itself. I picked up my facelifted tail lights for $75 on ebay, and now I know why, but thankfully I was able to fix them and ended up saving some $.

Gotta say, at least so far, getting the clear lights has been the best purchase I've made for the X. Next comes the sidemarkers, and then I take the plunge into Xenon/AE....


Here are some pics, badly taken and of poor quality, but you get the idea.

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Gone, but not forgotten:
2003 X5 3.0i - 135k - the most expensive club in the world.
Premium, Cold Climate, Rear Climate

Service History

Mods and Retrofits: Satellite radio, MediaBridge, DEPO HIDs + LED AEs, M-B W164 rear-light mod, clear corners, BSW x108 Subwoofer System, illuminated door handles, titanium grill, compass/auto-dim mirror

Traded 9/1/16 -- 5UXFA53533LV80809 -- If you know his whereabouts, please contact me.