The exterior lamp failure warning light is on in the dash in our 91 300TE. The strange thing is that I cannot figure out which light is out. The headlights, parking lights, license plate and rear lights are all on. To complicate the situation - this warning light is on as soon as I start the car, without turning the lights on.

Not familiar with what would cause this...anyone else have seen this?

Dome light? It might still be on by the time you start the car. Not sure how long the time delay is, but I think long enough to put on the seatbelt and give the key a twist. Slide the button to the 0 position, and see if it still comes on.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Sounds like the brake light, a lower or the high center mount.

to chime in... but there is a small bulb in the tail light... that one has caught me..

also license plate light....

it is not the obvious ones!

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1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

Don't forget to check the back up lights and left rear "fog (tail) light" too.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Aamge 55,

If you have not located the bad light yet, consider this:

Check which system the warning lights on either side of the "bulb out" warning light address (I think one is "low washer fluid", do not remember the other) and make sure those systems are working OK. If not ... for example, if your washer fluid is low, it may be because someone replaced a burnt out bulb in your instrument cluster and mistakenly put the "bulb out" bulb in the wrong hole - if so, next time you have the cluster out you will need to switch those two bulbs.

No need asking how I know this can happen.

If you didn't know, you are supposed to used the european wattage bulbs, not the domestic ones. How's your brakelight switch?

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

After going through each bulb, finding them all good. The warning light disappeared. Arrrrgh! It was after I checked the left rear set of light clusters it went away. Maybe it's like what Manny said - just a matter of seating it in the socket.

Nevertheless, it's off now. Still annoys me that I haven't found the cause.

a tiny dab , on the contact points (clean) ,of each bulb [and clean contact
points of each socket]will make this annoying situation less likely in the future.

I have had problems with the contacts in the left rear tail light assembly too. I think it was corrosion, because when I took all the bulbs out and hit the contacts with some very fine grit sandpaper, it went away. Hasn't returned for about five years now.

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

To ressurect an old thread, I have the bulb lamp warning lot on only when I turn on the lights on my new to me W124 Cab. I had a license plate bulb out, traced it to a bad wire in the hinge of the trunk and thought that would do it.

The license plate lights are now on, and all the other lights seem to work, but I still get the lamp bulb warning when I turn on either running lights or headlights. What am I missing?
Regards,
Jerry

You have found the cause...

...the metal rails inside the rear lamp housings that hold the bulbs in place vibrate loose over time. When that happens, there is a loss of "ground", barely visible as a slightly dim bulb here and there, but perceptible by the lamp indicator system as increased resistance.

When you went about inspecting the bulbs, you had reseated the rails by simply reinserting the bulbs firmly in their sockets. That restored a good ground connection, and all was well according to the system.

This one took months for me to solve...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

This post is only for Solidarity.

Yeah, I've been there too. For some reason, the cars I tend to dig are models known for (shall we say) "whimsical" electrical systems. My W126 is the car whose electrical system I can trust, at least; my Saab and my Cherokee, not so much.

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'88 300SE | Midnight Blue | 237k
'09 Subaru Impreza | red | 0k

Check to be sure that they are all the proper wattage, it is in your owner's manual and molded into the tail-light bulb holder.

The side-lights in the tail-lights are notorious. It is an outside light system only, not inside lights, and as it comes on without the headlamps or foglamps on I would eliminate them.

Can also be the lamp/warning module itself, open the cover behind the fusebox and it is the longest plug-in module.

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Gone to the dark side

- Jeff

I have the same problem in my 300TE. I am going to the junkyard next weekend to grab one of these units to see if it resolves it. My warning light only comes on when I turn on the headlights too. As said above, it is the long black one. There should be short ones and a long one...hard to miss.

Alternatively, you could always pull it out and check inside the box for bad solder joints. I did this to my Multi-Purpose Relay (The smaller one) and it fixed my wiper problems.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k