Help with w126 euro lights?
 

I found a set of bosch euro lights in the junkyard, and I finally installed them on my car, but one is so dim it barely works, and the other side works fine.

I checked several times that the wires are put in the new plugs in the right order, and I am sure that part is right. There is 12v at the pins in the plug where it attaches to the light, and 11.4v where the plug attaches to the bulb. Any ideas what could be wrong?

I am terrible with electrical problems, I know someone else could probably fix it in 5 minutes but I will most likely end up just taking them off and putting them in a box someplace and looking for another set of headlights later.

I'd start by checking all the connections for corrosion and proper tension if it is a spring loaded connection. then I'd check the ground for the fixture.

(I'm weak on electrical too). ...but corrosion and or bad grounds is the root of a whole lot of weird electrical woes.

Good luck!;)

Yup, check the grounds first.

-J

Well, the ground is in the plug with the power wires for the headlight, when I checked the voltage I used the ground and low beam power wires in the plug. The high beam is also dim, so a bad ground would make sense though. Any idea where the other end of the brown ground wire in the plug actually goes?

Brown is ground.

Where does the brown ground actually go? I know one end is attached to the headlight, but what is it actually grounded to?

You first must determine if you have a ground problem. The problem could actually be the reflector in the unit.Run a 12V lead and a ground lead directly from the battery to the bulb itself.See if the brightness improves significantly.

You'ld have to check the factory service manual, IIRC it's the little post on the radiator opening near the headlight.