S500 Highbeams work, but not low beams.
 

Hey whats going on guys.
I just want to thank you all in advance for all the help.
You guys are great!!

But yeah.

On the 1995 S500 I had just bought. While cleaning the engine compartment i think i bumped into something and now I noticed that the right low beam, and fog light arent comming on.

The left side low beam, fog light works. And both the high beams work.

Do you have any ideas what is going on? Maybe i bumped a connection. Or maybe the low beam bulbs are out?

Thanks....

Tony

On a Mercedes, there are four different circuits for the headlights. L/R and Hi/Low. Fogs usually run off on the four fuses.

Since one fog works and the other does not, sounds like you disturbed the wiring/connection.

Disclaimer: I've never worked on a W140.

Jim

There's a single connector that attaches to the headlamp housing. It provides power for all 3 bulb circuits contained in the headlamp (Hi, Lo & Fog) I guess you could have disturbed it to the point where there's a bad connection for 2 of the 3 circuits, but that seems unlikely.

Remove the headlamp access cover on the right side of the car. I'm pretty sure the plug is towards the edge of the car (rather than inward towards the motor). It will be rectangular in shape, black in color and it attaches by pressing it forward onto the pins.

There is no "clip" to hold the connector in place - good design and firm fitting pins do the trick.

Try unplugging and reconnecting the plug. If that fails to make any difference, start looking for burnt-out bulbs.

I'm pretty sure that on a 95 W140, the high beams are in the reflector closest to the grille. The fogs are below the main headlamp bulb, so you don't have a double filament hi/lo bulb. It should be easy to see if the filament is kaput.

There's a single ground wire inside the headlamp housing that provides ground to the lo and fog bulbs (I think) - it could be the source of the problem, but unless you've got moisture in the headlamp housing due to a bad seal or cracked lens, I've never seen corrosion issues inside the housings - the heat of the lamps tends to drive out the moisture.

i just looked at the headlights.
The driver side and passenger sides are totally different.

the driver side, the one that works is a 3-pronged item number 9003 hi/low filiment bulb.

Passender side has like three bulbs in it. A high, a low, and some other real small one.

All one pronged.

And its all jumbled up in there. I wonder if this is the original...

Anyways since the diver side is much more efficient. Im thinking of somehow changing the connections on the passenger side to a three pronged connector to fit one hi/low bulb just like the driver. Instead of having 3 different bulb.

What do you think? And do you have any tips on how to accomplish this?

The headlamp assembly that has 3 bulbs is the newer style. Maybe your car has had a replacement due to a broken headlamp lens, or a fender-bender? I don't know if the old 2 bulb style lamps are even available from MB anymore.

You cannot change the bulbs out - the reflectors are different styles and the housings won't accomodate the larger 2-filament bulb - plus I'd bet the light pattern would be off by a long-shot.

Just to confirm my suspicion - when you turn on the fog lights, where does the light come from. I'll bet on the headlamp with two bulbs, it comes from the reflector closest to the grill. From the other lamp, it probably appears below the main reflector - am I right?

I'd see about getting a new lamp assembly off e-bay. You'll need to get with a seller that's willing to confirm the lamp configuration. I'm pretty sure that the older style has a single large access door on the back, and the newer style has 2 doors. You can also try Nationwide Auto Recyling. They have several 92-93 era 140 chassis cars they're currently parting out. I've bought a bunch of interior parts for my car from them. Their prices are reasonable. If you don't see what you need, call them.

Good luck. PM me if you have further questions.