I have a 2000 S 430, and when my dash read "low Beam" I actually had to take it to the dealer to replace because of the new Xenon headlights, the bulb itself ran me $160.00!
If only the low-beam is out, you will need to replace the low-beam bulb. It is probably not necessary to replace the entire headlight assembly.
how to replace 2007 Mercedes GL450 Headlight Bulb Low Beam
A sealed beam headlight is just that. The unit is sealed and you replace the entire light. A composite is made of pieces that's why the name. To replace a composite you put a new blub in the back.
Carry it to dealer who will replace on low beam headlight for $15 +/- dollars in about 5 minutes.
The headlight has two filaments. One for the high beam and one for the low beam. The most likely reason the high beam is out is because the high beam filament is broken. Replace the bulb and it should fix it.
replace the high beam bulb
The Low Beam AND High Beam are in the same bulb. The procedure to change it will be in the owners manual.
replace passenger side low beam headlight
Yes, you can. I loosened and removed the screw on top of the headlight. Then placed a soft cloth in front of the headlight and gently pried the headlight straight out. It's just snapped in there. With some caution and patience you, too, can replace your low beam headlight lamp. Just don't scratch the top of your bumper after you've got it out and hanging by the wiring harness.
Phillips screwdriver from the front
Low beam is a 9006 bulb, high beam is a 9005.
replace the low beam headlight bulb