There is only one vacuum nipple on the headlight. I plumbed them as per Gary's diagram on Euro light vacuum adjustment.

With that, there is only one line going to (or from) the headlight housings.

The diagram illustrates that the headlight lines go to the lower nipple on the adjustment switch, which is what I have done. But if I do this, the lights do not respond to any change in dial setting. Actually, the lights do not respond to any dial setting in EITHER configuration. I did switch the lines already, still no go.

Found out that one line holds (and "regulates" perhaps) vacuum, the other does not. But I'm puzzled why either configuration does not work for the headlights, despite having confirmed movement when using the MityVac plumbed directly into the headlight housing vacuum lines.

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http://farm8.staticflickr.com/7271/7...144c3fc1dc.jpg

Please excuse me if this is off topic, but has anyone ever tried getting their euro vaccuum switch to be lighted? A while ago I bought an extra switch (I already installed one and it works great, only I set it so that the lowest setting is "0" and the other settings raise the low beams up a touch) that had the fiber optic cable that lights the icon above the dial. However, this fiber optic cable was very short. There is no way it would reach over the steering collumn and to the climate control panel. The cable I got is about 10 or 12 inches long.

Does anyone know what/where this fiber optic cable hooked up to in a euro car?

Thanks,

Gilbert

Thank you for the reply and thanks for the "rosette".

F

Can't say specifically for your car, but I've seen some older Benzes that had fiber-optic cables hooked up to one of the instrument cluster lamps.

Happy Motoring, Mark

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DrDKW

you're welcome

There should be a fiber optic "hub" in the switch panel above the A/C controls.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

yes but euro vacuum light switches don't have the fiber optic plug in them. you'd have to cannibalize it off another switch that does. and i believe not all w123's had the fiber optic option. actually i may be confusing that with the w116. i know the switches with the rounded corners started having the fiber optic, but the squared off switches didn't have it. so actually that started in the middle of the w116's production run.

My question was for a 1984 300 SD, so its a 126. Above the dial of my euro vacuum headlight adjuster, there is a lighted symbol for a headlight. When I bought my switch it had no fiber optic attached to it, but there is a place to put it to light the switch. So I bought another switch with the fiber optic cable attached, only this cable is no longer than 8 - 10 inches, so it will not physically reach all the way over to the A/C panel. The idea that there may be a place to plug it in on the back of the dash cluster sounds promising. That's about how long the fiber optic cable is. I will pull the cluster soon and try to find something.

Thanks you all,

Gilbert

If you can't find a nearby light source, like the instrument cluster or other lighted switch to route the optic cable to, you could wire a subminiature bulb & socket to the dash-lights, then mount it inside some small-diameter bit off metal tubing, and attach the optic cable to that.
Kind of a roundabout way to light just one switch, but if there's no way to acually have a light-bulb in that awitch, abd no other availible light source, it could be your only choice.

Happy Motoring, Mark

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DrDKW