Headlights Stopped Working W124 - PeachParts Mercedes-Benz Forum

zeronero · #1 01-04-2010, 10:19 PM

Hi, the headlights on my '92 400E stopped working today. Last time they worked was last night while driving home. When I went to drive to work this morning, before sunrise I went to turn the light switch on and nothing, no low or highbeam; except...

The foglights do work and the highbeam does work when the turn signal stalk it pulled towards the driver.

I checked to fuse and it's fine, a search of the forum didn't pull up anything.

compress ignite · #2 01-04-2010, 10:51 PM

The DMM (Digital Multi-Meter) will tell all.

Midnightlsc · #3 01-05-2010, 11:13 AM

I had the same thing happen a year ago on an E420. Headlights only all of sudden stopped working, but all other parking, turn and fog lights were fine. Replaced Multi-function switch and all is good since.

zeronero · #4 01-07-2010, 09:24 PM

Ok, I tested the plug at the headlights, and did a basic visual check under the hood, checking out the wires. Everything points to it being a faulty multi-function switch, which on this model is called a combination switch.

Think I'll have to pick one up, one question though; does the headlight switch every have any issues?

zeronero · #5 01-16-2010, 03:53 PM

I purchased a used combination switch on ebay, I received it a couple days ago and looked it over, it's looks as if it's almost brand new, which seemed good. Today though I went to install it, but before going through the whole procedure of taking off the steering wheel and lower dash panel I decided to test it by plugging it in to see if it would solve the problem.I removed the panel above the pedals and located the plug, plugged the new switch in, started the car, but to my dissapointment the same problem.

All the lights work, except the low and high beam. This leads me to believe that the switch I purchased it bad or there is some other issue. I emailed the seller to confirm that the switch does indeed work, but am wondering if I can test it myself? Visually the switch looks as if it's brand new, the mechanism also is very tight, not loost at all, which seems like a good sign, though I don't really know what the problem with these switches usually is, if its related to over use, a mechanical problem, or if the electrics just randomly go out.

As far as the problem being something else, could it be a relay, does this car, a 400E, even have a headlight relay? And does the headlight switch ever go out? What kind of electrical testing can I do I determine the cause? I really don't know where to start.

Uncle Acky · #6 01-18-2010, 11:28 PM

Please carefully check (remove and replace) the following fuses, F-2 - 16 amp. And all of the following 8 amp fuses f-8, f-13, f-14, f-15, and f-16.

hope this helps,
Acky

whunter · #7 01-26-2010, 06:04 AM

Quote:

Originally Posted by zeronero

Hi, the headlights on my '92 400E stopped working today. Last time they worked was last night while driving home. When I went to drive to work this morning, before sunrise I went to turn the light switch on and nothing, no low or high-beam; except...

The fog-lights do work and the high-beam does work when the turn signal stalk it pulled toward the driver.

I checked to fuse and it's fine, a search of the forum didn't pull up anything.

You description suggests the relay has failed.

In the rear section of your fuse panel there is a long relay MB# 126 542 01 32 (LAMP CONTROL).

Have a great day.

zeronero · #8 01-26-2010, 09:03 PM

I tested the new switch I purchased for continuity and it does work. I tested pins 1 and 2 with the switch in high beam position and pins 2 and 11 with the switch in flash position and when in those positions it did complete the circuit.

That's good new on that front, I'll test the original switch that's in the car to see if it's good also; it should be since the new switch didn't solve the problem and it works.

@whunter - It seems as if it might be the relay, but the fuses for the low and high beams aren't getting power. Since they're upstream of the relay shouldn't they still be getting power, or if the relay was dead even though downstream would that effect those fuses?

whunter · #9 01-27-2010, 06:52 AM

Quote:

Originally Posted by zeronero

I tested the new switch I purchased for continuity and it does work. I tested pins 1 and 2 with the switch in high beam position and pins 2 and 11 with the switch in flash position and when in those positions it did complete the circuit.

That's good new on that front, I'll test the original switch that's in the car to see if it's good also; it should be since the new switch didn't solve the problem and it works.

@whunter - It seems as if it might be the relay, but the fuses for the low and high beams aren't getting power. Since they're upstream of the relay shouldn't they still be getting power, or if the relay was dead even though downstream would that effect those fuses?

Try to find a good used relay, that is generally the issue.

timroperco · #10 01-29-2010, 12:46 PM

Your problem may be as simple as the main (dash) headlight switch. I had the same problem recently -- no headlights, upper or lower. However, when I pulled back the combo switch (signal stalk) I still got high beams.

Like most folks, when I turn the headlights on, I turn the switch hard right. What I discovered is the headlight switch itself was worn (120 M miles) and (I guess) went beyond its limit, thus cutting power to the headlights. By backing off he headlight switch to the left just a tad, I get my headlights back on. Also on my car, the yellow "bad bulb" indicator on the dash lights up if I turn the headlight switch too far to the right.

I just bought a new headlight switch from Peach Parts and plan to install it this weekend.

zeronero · #11 01-29-2010, 11:28 PM

Quote:

Originally Posted by timroperco

Your problem may be as simple as the main (dash) headlight switch.

Very true, though, I don't think that's the problem. My switch works perfectly for all other functions, and if I jiggle the switch (if that makes sense) it doesn't effect the headlights. I would imagine that since the headlight switch is mechanical it would slowly develop symptoms over time until eventually dead. In my case no issues with the headlights ever, then one morning they just don't turn on.

I followed whunter's advice and picked up a used relay off ebay that's been tested and has a warranty. We'll see by the end of next week if it's the issue, hopefully so

57farrell · #12 02-02-2010, 11:26 PM

My left headlight on my 300 ce will not come on most of the time. I have to get out of the car and gently tap it to get it to come on. I have used dielectric grease on connections. I think I may need to check the ground. All other lights function normally.

zeronero · #13 02-08-2010, 08:39 PM

Success!

So, I installed that relay I purchased and to my surprise still no headlights, I didn't expect that to happen. That lead me to believe that the light switch was the issue. I took apart the bottom section of the dash on the drivers side, removed the switch and tested it, it passed. I really didn't expect that to happen. The only cause now would be a wiring problem being the cause, located somewhere in the dash. Unfortunately since there are so many wires in that location it really wouldn't be possible to find out the issue. I figured that I would at least jiggle the wires to see if that might do anything, make a connection in someway, and to my surprise it did. I now have working lights.

As compress ignite put it "The DMM (Digital Multi-Meter) will tell all"

Next time I'll take the time in the beginning to test the whole system to find out where the problem lies, in this case that would have fixed the problem.

Thanks for all the help everyone!

mak · #14 02-08-2010, 09:38 PM

On my 300se the left beam would go dim after some time , it seemed like i bad ground or a corroded pin , everything was cleaned and reinstalled but the fault persisted.
I removed the ' good' fuse on that section and simply replaced it with a fresh brass tipped one. Fault rectified. I looked at the fuse under a magnifying glass and it became clear why the fault existed . The alloy tip had eroded away with age .I Replaced all the fuses with brass tip ones and so many rare And intermittant faults disappeared.
mak

mak · #15 02-08-2010, 09:38 PM

On my 300se the left beam would go dim after some time , it seemed like i bad ground or a corroded pin , everything was cleaned and reinstalled but the fault persisted.
I removed the ' good' fuse on that section and simply replaced it with a fresh brass tipped one. Fault rectified. I looked at the fuse under a magnifying glass and it became clear why the fault existed . The alloy tip had eroded away with age .I Replaced all the fuses with brass tip ones and so many intermittent faults disappeared.
mak