Coupe Headlights
Last week I thought that I'd check the headlight lamps since they have never been checked since I bought the car. What I
found is why this topic is posted. You may want to do some of the things that I did to your coupe's headlights.
Halogen Lamps
When I opened the back side of the main assembly, I removed a 80/100 halogen lamp with a dark blue coating. While it may be
'pretty', this coating serves as a filter allowing the lamp to produce only bluish-white light. Needless to say, it's very
inefficient since most of the lamp's output is filtered but what light is produced appears more bluish-white than from a
conventional halogen lamp. This doesn't make it better, in fact, the filter causes it to produce LESS light.
But this is just the tip of the iceberg. Suffice to say, I did some 'homework' so I could catchup on what's new in halogen
lighting for my Mercedes coupe. There's a lot of argument but after looking over the field, I chose the Sylvania 'SilverStar'
(SS) lamps, 9003ST. They operate at a very high temperature, around 4000K, which makes the light appear very
'white' and very bright, brighter than PIAA bulbs. Also they are LEGAL (use nominally 55/65 watts) for use in the
USA and Canada unlike the ones I removed. There are a lot of lamps that MAY be better but this lamp is available
almost everywhere and the cost is reasonable, about $29 for two. Light output for the 9003ST is
910/1500 lumens with maximum wattage 65/72 watts. The bad part is that the lamp's life is relatively short
when compared to a conventional lamp.
Sylvania says: "SilverStar halogen products are the newest products in the Sylvania High Performance Line. They are both the
whitest and the brightest lights available. SilverStar is whiter light, closer to the color of daylight. Whiter light helps
you see better at night and if your night vision is better, night driving is safer".
New Halogen Lamps: Silverstar Ultra
Recently Sylvania has released on new version of their "Silverstar" lamp solution for safer night time driving, called
the SilverStar® ULTRA. These provide up to 25% increase in down road visibility, increased side road visibility
and up to a 20% brighter light, compared to standard halogen headlights. They also last up to 30 percent
longer than regular SilverStar headlights.
The pure, white light emitted by the SilverStar ULTRA is closer to the color of daylight which helps drivers see better
at night. A study by the Rensselaer Polytechnic Institute (RPI) found halogen headlights that produce a whiter light can
help improve a driver’s reaction time and ability to see roadside objects at night. Price is $49 for a pair with a special
rebate of $20 until mid November. For my car, the Sylvania PN is "9003SU".
While doing this, I found that Sylvania also makes a SS version for the coupe's FOG lights, H3ST. So I replaced my
'stock' existing lamps with the new Sylvania H3ST. Same 4000K color temperature and very bright, white light output.
Price is $12 - $15 for a pair. Light output for the H3ST is 1315 lumens with maximum wattage of 65
watts."
Replacing Bulb
When replacing the bulb make sure that you do NOT touch the glass envelope with your hands. Since it's in a metal housing,
there is no need to contact it albeit by accident. To remove/replace the lamp, remove the cover above the head lamp and move
the metal retaining clamp to the top. Then remove the back cover. Next pull of the electrical connector off from the lamp.
Then release the two (2) clamping rings that hold the bulb into the headlight assembly. Replace the old lamp with a new bulb
and repeat the above steps in reverse.
One point here: It certainly appears that the car's wiring can take the additional current from the 80/100 watts lamps without
any difficulty. There was no evidence of burning or excessive heat due to the extra current draw from these hotter burning
lamps.
Manual Aiming
Now that I have all kinds of light, I noticed that the low beam from the driver's side headlight is pointed down and angled
toward the center. You say what's wrong with that?? It's supposed to be that way but mine was so extreme that the beam hit
the ground about 20 ft in front of the car! And it almost intersected the beam from the passenger side. Not very good! If
you think about it, the 'mis-aiming' was done intentionally because of the brightness of the previous lamps.
Understanding what is required for manual aiming of headlights will serve as a primer when you aim your Mercedes headlights.
This is probably one of the overlooked details after a lamp is replaced. Note that YOU DO NOT HAVE TO AIM the headlight if
it was ok prior to replacing the lamp. But if it's NEVER been checked or it looks like mine, then you need to aim both
headlights.
The manual process involves taking measurements and aiming the light against a wall or screen. During this process, park the
car on a level floor facing a wall or screen 25 ft away. To guarantee that you can see your headlight's pattern means
that you should do this at night! First, measure the vertical distance to the geometric center of the headlights. This is
the hard part -- what is the geometric center? On some lights, there is a little molded mark to indicate this center. On
others, it will be necessary to look into the lens and judge where the center of the bulb is. Transfer this measurement to
the wall. Measure the distance between the lights. Transfer this and the center line of the vehicle to the wall. Now mark a
line 2.1 inches below the horizontal you marked on the wall.
Turn on the lights and aim the low beams to intersect the lower line and the vertical lines where the angle in the beam starts
to slope upward as shown in the picture. The obvious problem with this system is all the time it takes. Not to mention the
difficulty of accurately making all of those measurements. Also, with some lights, the pattern of light on the wall is hard
to judge precisely.
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