Ok, folks, this one has me stumped. I have done a search on this forum and others to no avail, so here's the question. My 98 C43 AMG headlights have me baffled, in the low beam section there are 2 bulbs, 1 is obviously the low beam bulb, the other is the question...it never comes on! EVER! It is located directly under the low beam bulb (on either the left or right headlight assy) has a brown and a grey wire attached to it. Although the bulbs are good (checked with ohm meter) they will not come on no matter what position I have the switch in. What are they for?

The low beams work, the high beams work, the fog lights work, markers work, turn signals work, parking lights (left and right) all work, all lights work as advertised except these in question.

Is there a Mercedes genius out there that can explain this to me? I am pulling my hair out! Not really, just very very curious.

Thank you so much for your time.

Well, what size is the misterious bulb? If it is a small 5W bulb or similar it is definitely the Euro marker (the U.S. market use markers or "parking lights" as they are referred to in Europe at the turn signal assembly). In Euro and rest of the world the parking lights are installed within the main headlight assembly and besides providing parking assistance to view the car at darkness, they also provide a low light reflection on the headlight assembly when the low beam is burnt.

I assume that on your C43 AMG they just installed the same headlight unit as in Europe and per U.S. regulations it just doesn't turn on.

On previous M.B.s the U.S. and European headlight assemblies used to be completely different, but from the early 90's they are almost or exactly the same (except for the parking light issue).

Does this solves the mistery???

__________________
A. Rosich
CL 500, 1998
S 500 L, 1998
E 320 T, 1995 [Sadly sold ]

A. Rosich,

This explanation makes perfect sense. I feel somewhat the moron for not checking the wattage and/or model number of the "mysterious" bulb in question. Foolishly I visually compared the low beam bulb to the mystery bulb and they looked identical, as many bulbs do with completely different wattage, voltage, amperage, output ratings. Based on the visual inspection, I made an assumption... and we all know what that leads to........ . Anyway, as it is dark and raining here right now, first thing in the morning I will check the aforementioned criteria of the mystery bulb and report back.

Thank you so much for taking the time to help me in my quest for knowledge, and I am reasonably sure that tomorrow morning the "case of the mystery bulb" will be solved thanks to your efforts, and genius.

Until tomorrow, thank you again.
Matt

That should be for fog lamps. Do they come on when you pull out on the H/L knob in parking or regular H/L position? OR does your car have the fog lamps in the front bumper.

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Hi folks,
I checked the lights in question this morning and they are definitely not parking lights, they are 55w H1 bulbs. So now it makes sense that they would be fog lamps, but my car has the fog lamps in the bumper which come on when the switch is pulled out.

Are these supposed to come on in conjunction with the bumper fog lamps?

Or maybe the headlight assemblies came from a car that did not have fog lights in the bumper, but that would not explain the wiring because it is part of the chassis, not the headlight assemblies.

Any other ideas?

Thank you all for your wisdom,
Matt

Anyone?

Perhaps a previous owner did some mods or bought something off eBay that was 'almost' the right part??

Just a thought.

If you could provide us with a pic of your headlight assembly and if possible a picture of the location of the mystery bulb, it would help us a lot to throw a few guess ideas.

I sincerely doubt M.B. would install a bulb that does nothing at all (just imagine the cost of production and of parts wasted for nothing).

Just a stupid shot in the dark-> the Euro W220 had a peculiar headlight safety measure: when a low beam bulb burned, the fog lamp on the bumper would come on when the regular lights were turned on to compensate momentarily until the driver changed the burnt bulb.

Could this mysterious bulb be a back up???

__________________
A. Rosich
CL 500, 1998
S 500 L, 1998
E 320 T, 1995 [Sadly sold ]

It could well be that the AMG C43, which had bumper shell mounted fogs, used the same headlight assembly as the other W202, which had fogs in the assembly as well.