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Discussion Starter #1
what is it exactly that one needs to do to activate the vertical adjustment feature in the euro headlights??
 

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mercbuff - 3/7/2005 3:35 PM

what is it exactly that one needs to do to activate the vertical adjustment feature in the euro headlights??
they have knobs in the back, you use your fingers or you can use a table knife vertically and just keep turning it. Nothing too difficult.
 

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87 420SEL, 89 560SL, 92 300TE
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If you are talking about the adjuster on the dashboard, you need to hook up vacuum lines. They run from the vacuum source (intake manifold), through a "check valve" (a one-way valve) into the adjuster dial next to your headlight switch. If you have the US-spec headlight switch surround, this will need to be swapped out- I think Jonathan (jhodg5ck) will have these parts. If not, they show up on eBay quite regularly. From the adjuster dial, another vacuum line runs back to the engine compartment, through a "T" connector, then to the vacuum diaphragm connectors (a small tube) on the back of the headlights.

The "stock" spec is to set the adjuster dial at "0" and then have the headlights aimed normally. This gives three or four aiming points lower than stock, and one higher. You could also aim the headlights with the adjuster at the bottom, and have more "up" adjustment, if you want that.

Hope this helps!

-Robert
 

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OCStrider - 3/7/2005 5:38 PM

If you are talking about the adjuster on the dashboard, you need to hook up vacuum lines. They run from the vacuum source (intake manifold), through a "check valve" (a one-way valve) into the adjuster dial next to your headlight switch. If you have the US-spec headlight switch surround, this will need to be swapped out- I think Jonathan (jhodg5ck) will have these parts. If not, they show up on eBay quite regularly. From the adjuster dial, another vacuum line runs back to the engine compartment, through a "T" connector, then to the vacuum diaphragm connectors (a small tube) on the back of the headlights.

The "stock" spec is to set the adjuster dial at "0" and then have the headlights aimed normally. This gives three or four aiming points lower than stock, and one higher. You could also aim the headlights with the adjuster at the bottom, and have more "up" adjustment, if you want that.

Hope this helps!

-Robert
Thank you. I was thinking of going the whole hog and making them adjustable from inside the car, like they are on the Euro models.

Can you provide me with a detailed list of the parts required, and possibly some diagrams for all the vacuum lines / adjusters.

Would greatly appreciate it. Thanks again.
 

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Okay, the parts you need are:

Headlight Adjuster Dial (vacuum switch) -- first 2 images
Headlight Switch Surround (panel around headlight switch - adjuster dial clicks in) -- third image
Vacuum Check Valve (should be available at any auto parts store)
vacuum line (the small, hard translucent plastic line- the MB stealerships carry it at a reasonable price(!))
vacuum line (the somewhat larger rubber line - for connections)
Euro Headlights (of course)

The fourth image is a rough schematic I drew up. You can use any manifold vacuum source- there should be one or more vacuum fittings on the manifold that are capped off. You can remove the caps and use any of these. Or, you can "splice into" a vacuum source (the closer to the manifold the better) and use a "T" or a "Y" connector. The check valve is mounted in the vacuum "supply" line ahead of the aduster. It should only allow air flow TOWARDS the engine. There are several "bushings" passing through both the inner and main firewalls that you can use to route the vacuum lines. Also, you should maintain "equal volume" in the lines between the headlights - that means that the headlight lines should be the same length. The rear of each Euro headlight assembly has a small tube near the electrical connectors that is the vacuum port to the diaphragm inside. If you remove the back cover of the headlight, you can see a vacuum line inside the assmebly- follow that back and you'll see the connector. To make sure you have the right line and that it works, put a short length of the rubber vacuum line over the vacuum port and attach a small vacuum pump to it - or just suck on it. You should see the headlight reflector moving.

Its really not a hard project. I'll post pics of my setup as soon as I get a chance to shoot some. These are various images that I found on the web. Please note also that the markings on the headlight adjuster switch do vary - mine is labelled (from the top) +1, 0, -1, -2, -3.

Let me know if this is unclear! The adjustable headlights are a very cool mod- I love mine!

-Robert
 

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thank you very much........i'll attempt this project in the coming week.
 

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can someone give me the part number for the 'plate', that both the light switch and adjuster fit into.

and is it the same part for both left hand and right hand drive cars, or different?

thanks.
 

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Thanks for all that info OCStrider.
I have a problem with the headlight vacuum height adjustment on my 88 420, or more specifically, losing vacuum under load.
When accelerating, the lights dip down so i figure the one way valve is leaking and not holding the vacuum.
Any ideas where this valve is?
There is one in front of the brake booster on the firewall, but the line to the headlight switch branch off before the valve. One line from manifold, three branching off this line through firewall, the middle one to a check valve, one of the other two to the headlight switch.
So i figure there is another one inline somewhere else before the headlight switch.
Anyone know where it is please, of if this is not the cause, what might be?
Thanks in advance.
 
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