OhioS55

First post to any forum - hope I am doing it right or close to it. I have been searching these forums on various subjects since I got the S55(k) this spring, have found some good information that way and solved various minor problems. This is a problem I haven't been able to solve, and since I have been looking into it for some time, the post is a bit long.

The OEM xenon projector low beams are very dim. They light up and stay on but are not even close to usable, can't drive the car at night. Have replaced bulbs of course, with the correct Philips. Both sides are exactly the same, on but dim. Insides of projector lenses were not really dirty but I cleaned them anyway, with flexible tubing and cotton.

The local MB dealer shop is useless (everyone will probably be astounded by this). A local indy shop is willing to work on it but can't find any electrical schematics. They went to all their sources of such info and were told "MB does not publish a schematic for this car" whatever that means. I have tried WIS but am no good at running it to begin with, can't find anything, could be just me. Incidentally, EPC finds my car but WIS doesn't.

The subject of xenon headlights is confusing but after reading quite a bit this summer, I believe what I have are officially bi-xenon since the projector unit has an electric "flipper" that elevates its weak output a little when the high beam comes on. But another separate high beam bulb comes on too, a good old light bulb in the next socket over, which works fine - just like any other car (I wish the low beam was the same). So when the high beam is on, I have both the xenon projector and a separate light bulb going at the same time, bright as daylight, although the xenon projectors are contributing next to nothing.

There don't appear to be any motors in these lights, which I believe is possible because the car has ABC.

Since the bumper cover has to come off to get these units out, which I can't do myself, it's a little difficult to decide what to do. The cover will have to come off in the shop and the car will be stuck there until the problem is solved or abandoned. I could try used ballasts from ebay for about $150 each but I wonder how likely it is that I have two bad ballasts that both successfully drive the ignitor to light the xenons every time, which they do. As I understand the basics of gas light bulbs, an initial high voltage spike jumps the gap and then a much lower voltage keeps the light going, in this case about 15,000v initially and then 85 volts. No apparent problems with the high voltage. As far as I know there is no way to measure the 85 volts although I would like to.

These may not be the original headlight units. EPC says the car has 220 820 51 61 and 220 820 52 61, but the lights I have are 220 820 35 61 and 220 820 36 61. These last two numbers are referenced in a 2005 post as 2006 parts.

I am not interested in upgrades or aftermarket anything, just want the car to work like it should. I hope someone has a suggestion and/or a schematic diagram for the headlights. Thanks for reading this.

w4sim

Im no expert in electrics but can an auto-electrician not locate the problem? Most xenon lights work the same way and so are pretty generic in design from a power point of view. The auto-electrician might not need diagrams specific to this car to work it out.

Iv just recently found out myself that in about 2005/2006 Mercedes re-numbered some of the old part numbers with new numbers, but the parts are actually the same. It could be that the previous guy had the same problem and decided to change the whole headlight unit? or maybe something happened to the original headlights and when the new ones were put in something wasnt wired up correctly? Just thinking out loud here.

Either way there seems to be a problem of power, or rather lack of power getting to the lights. Has this been a problem ever since you got the car or were they working fine when you first got it? Can you not speak to the previous owner?

It might not be a lot but i hope this is of some help.

hegar817

i sure hope there is a fix for this as I also agree that w220 HID projector lights do not put out enough light. I changed out my projector lenses to the ZKW lenses off an Acura TL but did not get much improvement. It is fairly noticeable but not worth the time and risk you take to damge some of your headlight parts and condensation build up if not sealed right.

OhioS55

I have continued to work on this. I may have approached this the wrong way - I assumed there was something wrong with my lights. I am now wondering if none of them are any better. This is the only car I have driven with HID lights so I have no previous experience to compare. The first step was of course to replace the xenon bulbs with the correct Philips parts.

I suspect the car's previous owner may have heard the same proposed solution to this problem from a MB dealer that I got from one here - replace the headlight assemblies for upwards of $3000 - and went for it. The car, a 2003, seems to have 2006 lights.

I am an electronic technician in a field unrelated to cars or lighting. I did some cursory reading on the subject of HID lights and learned that: A high voltage is generated to start the arc that produces the light; once the arc is started, 85 volts AC maintains it. This matches markings on my ignitors, the orange cube shaped devices that attach to the xenon bulbs. This is similar to the way any fluorescent light works. I learned that it is theoretically possible that, once started, an AC voltage much lower than 85 could keep the arc going, which would likely cause low light output. I decided that I needed to know if my AC voltage was low or not.

I made a test rig from a pair of xenon bulbs (I have spares from earlier in this process) and neon sign high voltage wire, so that the operating bulb would be extended from the ignitor, and outside of the headlight assembly. Once the bulb is lit and running, the high voltage is gone, so a regular voltmeter can be touched to the leads. There is some risk here, but I am not uncomfortable around high voltage and have some practical training and experience, in addition to a tendency to interpret safety warnings as affronts to my virility. There is more risk of setting the car on fire than electrocution. I put the car outside and away from the house in case something went wrong. I measured exactly 85 volts AC.

So my xenon bulbs are apparently operating as designed, electrically. It seems to me that the only potential problem left, if any of these lights are any good, is the projector. The back side of the projector lenses are clean. The focal length of the projector assembly is not likely to change. It is possible that the inside of the reflector bowl where the xenon bulb resides is not reflective for some reason. I have ordered a small diamater medical mirror and will inspect this surface.

It doesn't seem likely that I will get any improvement. I am more concerned with function than appearance - we want to use the car for extended highway trips. If I could be sure that a set of non-xenon lights from an older car would fit mechanically and that the electrical connections would plug in, I would replace the assemblies and accept the "look". I have read that the computer can be set to accept either type of lights. I plan to order a CD/DVD from Mercedes that is supposed to contain W220 electrical diagrams. Maybe I will be able to figure out old part numbers that will work.

OhioS55

I finally found the problem. Using mirrors to look at the inside of the low beam projector reflector bowls (from the back, through the light bulb hole - this is not easy with the lights still on the car) I found that the reflective material has turned to some kind of brownish black crud. I twisted up some pipe cleaners, made sort of an elbow out of them, and cleaned some of this off, but the result is the dull gray surface of the cast metal bowl, not much help.

So all my electrical testing accomplished nothing - the xenon bulbs are working fine, but the light can't get out front.

If they ran so hot that the reflective layer burned off, I would think that the outside of the metal bowl would have been just as hot, but it looks perfectly shiny.

There is apparently no way to get the projector assemblies out of the headlight fixture without baking, prying, etc. and I can't even get the lights out without taking the car to a body shop, so I don't think the lights I have are fixable. And, if these lights have been replaced before, as w4sim suggested, with 74K on the car now, it looks like these things aren't good for long anyway. There must be a lot of S-class cars with weak low beams.

I have looked at various aftermarket light assemblies. Some suppliers are helpful enough to state that their lights won't work on cars with factory xenon. Others' who don't specify this probably don't either. I hope to find something that will not only fit but plug in without cutting up the wiring. This may be difficult. I assume there are far fewer S55 AMG's than the various other S models, and I seem to have somewhat odd lights in that they don't have autoleveling motors.

Even if the price of MB headlights wasn't so ridiculous, I think I'd rather try somebody else's and see if they last longer. The car will soon be put away for winter so this may be put off until spring. If I find replacement lights that work out I'll put up another message. Thanks for the previous responses.

hegar817

I think pictures would help us understand where the yucky stuff was located at. As far as removing the headlight from your car, no need to go to a body shop. All you need are some basic tools and a little muscle as you will not break anything just have to wrestle with the front bumper a little. You will need to bake them in the oven in order to pry off the glue that keeps the housing in contact.

OhioS55

My 2003 S55, bought last year, had extremely weak low beams (xenon). High beams (H7) have been very good all along but you can't drive around with high beams on all the time. I figured out how to get the front bumper off and the headlights out of the car. These assemblies are clearly not designed to be taken apart but I did it. I found two reflectors on ebay, called BMW but they looked right, and in new condition (photo of the old reflectors attached). With much difficulty, I reassembled the headlights with the ebay'ed reflectors, which fit perfectly.

The car has been stored for the winter, but will soon be out again, and I will find out if the low beams are any better. They look good on the garage wall, but they did before too - out on the road in the dark they were useless. Since the mechanical adjustments on these lights don't have to be changed to remove the whole assembly, I haven't done any alignment. The vertical cutoff line is at the same level on the garage wall as before.

I read some descriptions of taking these lights apart that mentioned heating them up in an oven to soften the glue. My lights were glued up with butyl rubber, which might get softer when warm but I was able to separate the assemblies at room temperature. I used wooden paint sticks to pry with, and by giving the glue some time with each pry, they came apart. The worst problem was that when separating the clear lens from the fixture, the glue would "string" like pizza cheese, and some of the strings got on the silver coating on the many silver coated plastic parts inside. This silver coating is incredibly fragile in my lights, and any attempt to remove the glue strings with q tips and paint thinner etc. discolored or removed some of the silver coating. It may have been better to warm the lights, which may have kept the glue from "stringing", I don't know.


I decided to throughly clean all of the old butyl rubber glue out of the channels before putting the lights back together, because the outside of the glue bead was packed with dirt. This was extremely time consuming but paint thinner does eventually dissolve the glue. I used new butyl rubber and sealed the lights back up as well as they were before, I think. I haven't had condensation problems inside my lights, but if I did I would think removing the covers behind the lights where you change bulbs would let any moisture dry out in a few days.


When I started looking into my low beam problem, I thought the price of new OEM lights was ridiculous, and there had to be another way. I didn't find many positive opinions about the many aftermarket lights available, and that is of course a fairly complicated subject itself - OEM xenon, add-on xenon, connector compatibility, leveling motors or not, and so on.

I don't make nearly enough money to buy a new car like this, and probably not enough to own an old one either, but I didn't realize that when buying it. Since the car's value is so low, I was able to get it. If I counted up all the time I spent researching xenon lights, then how to get them out, the reflector replacement job itself, and putting the car back together I would have been better off to have bought new lights, and let a shop put them in. And what I am left with are used clear lenses that aren't too bad but not new.


In the attached photo of the old reflectors, the silver coating on the inside has turned to some kind of goo. The one on the right has been cleaned, the other not. Cleaning just exposed some now-unshiny silver and some of the pot metal surface, which didn't make any improvement in the perceived light output. I managed to do this cleaning when the lights were still in the car, with bundled-up pipe cleaners. I suppose the new/ebay reflectors I put in will look like this eventually.

This car overall looks really good, but all I care about as far as the lights is that they are useful. Assuming that the new reflectors have made the car drivable at night for the near future, when I have to get into this again I think I will try to come up with aftermarket replacements that fit the car correctly but use H7 bulbs for both high and low beams. To that end I drew out the wiring while the lights were apart, for future reference.

I will put up one more (short this time) update when the car has been out at night, for the real low beam test, which would be not running off the road or into large objects. BTW I have used the fog lights, which can help, but they are pointed so low that it doesn't seem safe to go faster than about 35 mph in the dark.

OhioS55

I was able to get the S55 out of storage today, and went for a night drive to test the xenon low beams, with the replaced reflector bowls found on ebay. I tried not to expect too much so I wouldn't be disappointed. The result - absolutely stunning amount of light, I have never seen anything like it. This is the only car with xenons I have ever driven. Turning on the high beams is hardly noticeable now, other than the color difference (they are H7 type) and elevation of the HB's.

I probably should have spent the $ and got the lights replaced as soon as I got the car. It takes a while to accept the cost of some repairs on the W220 I suppose. I put a lot of time into this repair and got it done eventually, cost in parts about $50. A small victory, this time.

w4sim

I think with the job involved, the end result and the satisfaction that must have come from the job itself id personally say its a pretty big victory with small costs.

This could have cost a HELL of a lo more to do, and i think if it was an average guy with limited electronics knowledge he would have thrown the towel in some time ago.

Very glad you got it sorted it though, i think you deserve a pat on the back.

hegar817

Did you replace the lenses or the reflectors that look like cups in you picture above? If you replaced the reflectors, what model car did they come off and how did you get them off? I also thought that our cars have d2s bulb sizes.

Thanks

OhioS55

I replaced the reflector bowls. The original lenses were fine - made of glass, so not much could happen to them. I got lucky and found bowl and lens sets on ebay, although I only needed the bowls. The ad just said BMW Mercedes, so I don't know what car they came from. The seller must have had reason to believe that some BMW's use the same reflector. I had looked at the backs of my headlights (still on the car) with flashlight and mirrors enough that I believed the ebay reflector bowls were the same, although I had no part numbers or anything else to judge from. I don't know why the replacement bowls, which were almost certainly used, did not show any signs of the reflective material deteriorating like the originals did.

The coil boards on the little flipper doors on the ebay units were different, so I used the original ones.

I would think that broken headlights from a collision could be a source for reflector bowls. They are mounted in a plastic frame within the light fixture, which does the adjusting, so they would likely survive a fairly bad crash. This may be where my replacements came from.

My lights use D2S xenon bulbs for the low beams, and a separate reflector with H7 halogen bulbs for high beams. What I call a "flipper door" is part of the xenon low beam bowl/lens assembly, and it has a solenoid that is energized when the high beams come on, apparently to change the elevation of the low beam. When the H7 high beams are on, the xenon low beams are also still on. I might pull the H7 high beam bulbs sometime to observe what effect the flipper doors have on the xenons alone when the high beam switch energizes the flipper doors, but haven't done it yet.

I believe from reading various things during this project that some cars use a single xenon bulb for both high and low beam, and the same light output is just redirected.