I have a 2005 C55. Yesterday, I got the Low Beam Headlight failure message, adn noticed the driver's side low beam was out. I later came back to start the car again, and the low beam flashed a couple of times and then went out and stayed out.

I understand this is a fairly common occurrence, but I'm a bit confused by the postings in the forum about this problem and would appreciate some advise, as I understand that going to the dealer with this could mean a $2000 replacement of the entire headlight unit.

1. Is there a good after market replacement that would not cause flickering / metling problems some here seem to have experienced with after market parts? If so, can I get a link or name?

2. Does the C55 come standard with Xenons? I have Xenons, but don't know if I can "plug and play" replace those with "Bi-Xenons" - which I assume means both high and low beams are Xenons?

3. Anyone have a DIY on removing the headlight unit?

4. Is it advisable to first try replacing just the bulb, and if so which bulb and where to source would be appreciated?

5. Also, can I get a DIY on the turn signal light removal for a W211? I have W211 with turn signal out, and I know this is the wrong forum, but in case anyone here has "been there done that".

Thanks in advance, and don't forget to vote!!!

 

There's a good chance your headlight ballast went out. I don't know if it's a defect with the headlight housing, excessive heat in that area, or excessive pass-through electricity, but the driver's side ballast is notorious for going out. I'm on my third or fourth one now (110,000 mi; 2005), I just finished replacing it a couple weekends ago. My previous replacement was a used one that worked well and lasted about 2 years. I just bought a brand new one on ebay, look up this item number (#110751213377). So far so good, hopefully this one lasts another few years. No problems with the passenger side.

The ballast is bolted to the bottom of the headlight; the headlight connector is imbedded in the headlight, so you just pop off the three screws and it comes off.

To get the to ballast is the hard part:
1) Remove wheel
2) Remove the lower fender liner, which includes removing a few (more than 6 or 7) push pins from the wheel and underneath the car, and a few bolts (3?)
3) Remove grill bolts (2) and grill (I have CLK grill)
4) Remove fog light grills (U-clip) and remove 1 bolt behind each
5) Remove bumper bolts (2) from overhead near the inside headlight
6) Unplug fog light connector (from underneath where you took out the fender liner)
7) Remove bumper to fender bolt from inside the fender liner (I hope you're a thin guy with thin arms/hands)
8) There is a long bracket/clip that clamps the fender to the bumper along the entire length of the fender/bumper gap. It needs to be pryed inboard to the car, then pulled rearward to "unhook". Once you get it out you'll see what I mean.
9) Remove the two bolts holding the top of the headlight.
10) Pull forward the bumper just enough so you can see the side bolt holding in the headlight. You're going to need to pull forward to "unlatch" the bumper, and immediately after you're going to need to pull outward to unclip from the fender.
11) Remove the side headlight bolt.
12) Pull the headlight up and out as much as you can. Unplug the wiring connector. There may be an additional vaccuum line looking connector; I was never able to remove this vaccuum line so I just twisted around the headlight.
13) Rotate the headlight so you can see the underside where the ballast is.
14) Remove the three screws holding the ballast to the headlight (the ballast will fall, do not let it chip your fender).
15) Reverse! 1-14.
16) Turn the car on, take it for a spin around the block to let the leveling sensor do its thing.
17) Aim the car against a wall to check levelness against the passenger side
18) Open the hood back up, use a large (I think it's 8mm) hex allen key to adjust the headlight up/down. This is the large black connector near the middle of the headlight. Do not remove the plastic cover to reach the other adjustment wheel. I don't know what this is over, but you're going to break it trying to get it to it. I tried, and you don't need it because your up/down adjustment is already in your face.
19) Close hood, drive around some more, admire your work and go tell your wife you just saved her hundreds of dollars.

If you have any questions PM me.

 

Wow! Thanks for that input and for the detail. You have obviously "done that" - very much appreciated. I'll pick up the part and give it a go or have my indy do it with your guidance cos I'll probably break something. Cheers!

 

Viper98912 - Nice write up on how to change the ballast.

X55 MGR - Try some basic trouble shooting using Viper98912 write up to get to the parts in question before buying a new ballast.

Test 1 - Swap the ballast from the passenger side to the driver side, and driver side to the passenger side as they are the same, see if the issue still occurs in the same headlight. If the issue moves to the other side then you know its the ballast.

Test 2 - If the issue still occurs in the same headlight after swapping the ballast try swapping the xeon bulb from the passenger side to the driver side, and driver side to the passenger side.

If the issue still occurs after trying both those swaps individually then it might be the level sensor/motor that is built into the headlight which you need the entire headlight assembly for.

These are the same trouble shooting steps the dealership uses to troubleshoot the xeons that have issues randomly turning off, or flickering. Mine turned out to be the level sensor/motor causing the flickering and randomly turning off. Since they replaced the entire headlight assembly I've had no issues.

Good luck trouble shooting, let us know what the issue turns out to be.

 

great writeup!

 

Great idea. I'll do the trouble shooting first. Thanks for that suggestion!!!

Between you and Viper98912, I feel like someone just put cash back in my pocket.