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Discussion Starter #1
As above, is it a fuse or relay problem? I searched under dashboard but nothing shows up unless buried deep in a thread.

Hand Brake warning light comes on, indicators too, but no other instrument lights or light for headlights etc come on. No lights on dials for heaters, window switchs etc on central console light up either. The instruments all work.

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There's two knobs in the instrument cluter, just near the outside temperature gauge (if you have one).

The left one, its a rheostat which changes the resistance of the lights from low to max. Sometimes it doesn't make contact and all lights go off...

Turning it to the right makes brightness the lights, turning it to the left, dims the lights.... So just wiggle it a bit, all lights should come up.

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Discussion Starter #5
I tried the dimmer switch on cluster but nothing happened, so the circuit board issue does that affect central console switch lights/illumination?

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Cheers guys, will get my mechanic onto it sooner rather than later.

Another little issue, also on the 200TE Mercedes, when I put on the tailgate screen demister, the switch light stays solid for 2/3 seconds then starts flashing, handbook says alternator output low or too many electrical components on, but car starts first turn of key, no other circuits actually on at same time, thoughts?

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1989 W124 300CE same problem. All my switch lights worked fine as did the dimmer. I replace the blower switch light with an LED but it turned out to be a blue color so removed it and now none of my switch lights work. Looking at the terminals on the LED they appear to be just open wires and not sealed into the light. I must have shorted someting. The fuse no 3 is fine but I replaced it just in case. Still no lights. There has to be another fuse somewhere.
 

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Had the same issue, tried wiggling it etc, the fuse was fine, in the end I replaced the potentiometer, my mechanic gave one to me (not too expensive though). Didn't try the cleaning or anything.


It's an easy fix, the hardest part is getting the cables loose on the rear of the instrument cluster and getting the cluster out of the dash if your wheel isn't adjustable. You need special ish-tools, https://mercedessource.com/store/r107-w116-w123-w126-w201-w124-r129-w140-instrument-cluster-removal-tools but if you take a look it should be easy to fashion one from like a metal coat hanger or something.



Mercedes w124 Potentiometer for Instrument Lighting GENUINE +1 YEAR WARRANTY | eBay
 

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Hi Everyone.

Recently I tried to change a bulb and then suddenly all of dash lights and Console lights were gone.

I replaced 5A fuse and rheostat on cluster but still no lights.

I checked from circule board but I could not find any wrong.

Should I need to relace light relay????

My car is 1995 E320.
 

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And have you replaced ALL of the fuses inside the main fusebox with the updated copper core ceramic type?

BTW, which bulb went bad and did you replace it with a identical type from a quality brand such as Philips, OSRAM/Sylvania.

These cars do not take well to lighting mods such as LED conversions, etc.
 

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Yes I replaced new Copper ceramic fuse from main fuse box specially No 5 which related to instructment and I tried to switch Osram bulb. I do not know really why suddenly no lights all of console lights too
 

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I have a similar problem.

I put in LEDs for the dash lights, so really no need for the dimmer/rheostat, so I jumped it.

Now i have dash lights, but no other lights (HVAC, PW switches).

Anyone else have this issue?

I replaced the headlight switch and still no change.

Also changed the little red fuse. No change.

Looking at the wiring diagram, what is that that I have pointed out with a question mark???

Clipboard01.jpg


I think I have an N40 unit that's out since half my stuff works as aforementioned.

This thread is interesting:

 

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Instrument cluster is most easily removed on the cheap with those thin tools they usually give you for removing/installing a new HU.

Kevin
 
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