Hi,

the yellow light in the cluster, indicating outside light malfunction comes on intermittently. I cannot find the cause for that. All lights seem to work fine- even the license plate ones.

Today this think came on during the daytime with the lights (switch of course) turned off. So I have two questions -
1. Is it indeed only for outside lights ?
2.could it be shorted somewhere, somehow?
Has any one encountered a similar situation ?

Thanks

1987 300SE Euro

You have an intermittent fault. Probably corrosion in the bulb sockets.

I would take off the covers from your rear taillights (in the trunk) and pull each bulb out. Check for corrosion in the connectors, lightly clean with steel wool, then put a light coating of silicone dielectric grease in each socket.

If doing the rears doesn't fix the problem, then do the front bulbs. The rears are easiest to access, so start there.

Hope this helps. If this doesn't fix it, you'll need to start chasing down a wiring fault. This will be a little harder since the problem is intermittent.

Neal

__________________
'83 300SD 335,000km (207k) mi SOLD
'87 560SL 163,000km (101k mi) SOLD
'86 300SDL 356,000km (220k mi) SOLD
'92 500SEL 250,000km (155k mi) SOLD
'90 300SL 140,000km (87k mi) SOLD
'01 S430 260,000km (161k mi) SOLD
'03 SL500 167,000km (104k mi) SOLD
'07 S550 4MATIC 235,000km (146k mi) SOLD
'07 GL320 CDI 4MATIC 348,000km (215k mi)
'13 GL350 BlueTec 4MATIC 170,000km (105k mi)
'14 SL550 72,000km (43k mi)

I had an intermittent indication recently.

I found that the left front marker lamp was not on when the fault light was on. I bought a new bulb, and waited. It mysteriously repaired itself at least 10 times.

On the eleventh try, it failed and didn't repair itself, as the fault light stayed on. I finally replaced the bulb and no more fault.

When I looked at the filament, it was indeed broken from one holder. My guess, it broke from the bottom and as it dangled and jiggled around, it sometimes contacted the rest of the filament and temporarily welded itself back together. Sometimes it would happen once or twice over a bumpy stretch of road.

As far as I know, it is indeed for outside lights. Since the switch was off, I'd suspect a brake filament, since unless you have a helper step on the brake pedal, you won't see a bad filament outside yourself.

Corrosion, as mentioned, is possible, as is a bad filament. Pull 'em, check 'em, clean 'em, and replace 'em if in doubt.

Best Regards,
Jim

The easiest thing to do FIRST is to check and clean the fuses and particularly their contact points. There is a good chance that one of the related fuses, or its contact point in the fuse box is corroded, causing intermittent problems.

Its an even better idea to change these fuses. Mercedes fuses are notorious for corrosion, and hairline cracks.


Phil

__________________
'95 E300 Diesel, 264,000 Miles. [Sold it]

The relay in my SDL would illuminate the warning light if I took a hard right turn. Sometimes after hitting a bump or pothole. I had a friend redo the solder joints and it's been fine since.

Sixto
95 S420
87 300SDL

I will roll my sleeves up and go after the warning light this weekend.
I will do the fuses again , cause it is time. - though the cluster fuse seems to govern other things that have not been affected...
I will do the tail lights even though they are all working - including the brakes. tried that with a helper.The bulbs looked good. Of course the car was stationary when checking, but still the lights work and at the same time so does the warning light. Away with tail light corrosion !
Sixto- The relay option is interesting - Which relay are you referring to ?
Thanks and I Will report with any good results.

The relay I'm talking about is the long box in the fuse box in the engine bay. In LHD cars anyway. It's the brains of the lamp monitoring system.

Sixto
95 S420
87 300SDL

1. The bulb monitor is only for outside lights.
2. My bet is that it is bulb/socket corrosion or faulty (intermittent) bulb of one of the brake lights (right, left or third). This is because the fault shows up with the lights off (you may have been using the brakes, no?).

__________________
Steve

1992 300CE Sportline Sophie
1990 300E Emma - in the family
1979 240D Josephine - sold, but not forgotten
2004 Pacifica AWD

http://web.mac.com/dakota/Mercedes/Home.html

I had the same problem. Drove me crazy! I finally figured out that one of the rear lights had blown the filament that only lights when the brakes are used. I couldn't figure it out because it would not come on until I hit the brakes and then would stay on. Please check this first before you spend lots of time, aggravation, and money like I did.

Forgot to say that the bulb "looked" o.k. and even worked sometimes. The filament had broken in a way that it sometimes made connection and sometimes didn't.

I cleaned all possible corrosion spots in the rear and in the fuse box.
replaced some of the fuses and cleaned the others. I figured it was good preventive action if anything.
Took the car out for a ride - the yellow appeared suddenly - and would not go off until I turned the engine off. That was Friday night.
Saturday morning I went out for a long run and gave the car an Italian tuneup at the same time. - The yellow monster Light never came on...
So today I will replace the rear brake bulbs as suggested here and if that doesn't do it I will go for resoldering the big black relay box. Thankfully I know this is really a minor issue - but failing to resolve it, does drive me nuts...

I must have done ok with all the good advice I got here.
The yellow light has gone into hiding for now....
thank you all !