W124 300D Dashboard Warning Lamp "Bulb Out"

[nvestor88]

90 Turbo D Dashboard warning light constantly stays on. I checked all my bulbs and lights. They all see to be working. The only one I noticed out is the one for the shifter that tells you what gear you are in. Can this one be the cause for the light out warning to be on? Where is this bulb located? Thanks

[compu_85]

You sure that both of the liscense plate lights are good? All the ones in the 3rd brake light? Does the failure lamp turn on as soon as you turn on the key? Only with the headlights on? After you press the brake once?

-Jason

[BodhiBenz1987]

On my 87, the warning light won't tell you about console lights, dome lights, cluster lights or courtesy lights .. I had the shifter bulb fail and it didn't trigger any warning lamp. However, the shifter is fairly easy to change if you want to do it anyway ... lift off the wood carefully, unscrew the top off the shifter box, and there's a little bulb in there.

Have you checked backups and brakes? I usually do this by backing up in front of a store window to see the reflection. I did have a rear side marker out once that I didn't catch on first glimpse .. and yeah license plate lamps are pretty easy to miss.

[compress ignite]

BB'87 is correct the Relay only senses and alerts you to Exterior Lamps Out.

The FSM suggests making sure all the bulb clips are FIRMLY grasping the bulbs.
(If necessary bend the clips inward SLIGHTLY)

I discovered some P,W (Poof,Wanker) had attached a trailer light harness with
"Scotch Locks" on the Rear Wiring Harness and the "Lights Out" relay didn't like
"It",so it signaled it's displeasure by illuminating the Dash Cluster light.

Some on this forum have suggested the LO Relay is sensitive enough to Alert
on high resistance bulbs that still "light up".(These are the OEM Osram Bulbs,
but going bad.)

If someone has replaced the bulbs with non OEM type (and/or Wattage) the
LO Relay will Alert that way Also!

[awsrock]

For me, I had a lisence plate light out, but only when the trunk was closed. I'd open it up to check, and it would be on. Turns out there is something wrong with the main wire that when the trunk cloese, it bends a certain way and shuts only that one off. I gave up on trying to fix it So, it could be something like that, tricking you

[Jeremy5848]

Originally Posted by awsrock

For me, I had a lisence plate light out, but only when the trunk was closed. I'd open it up to check, and it would be on. Turns out there is something wrong with the main wire that when the trunk cloese, it bends a certain way and shuts only that one off. I gave up on trying to fix it So, it could be something like that, tricking you

We had something similar in our '96. Turned out that one of the parking lights had an intermittent filament. Whenever you looked at it with the car parked, it was fine. When you drove the car, the filament would wiggle just enough to set off the sensor.

Jeremy

[sixto]

It might be a bad relay if the bulb is on all the time. The bulb should be off when you first start the engine then come on when you switch on the circuit with the bad bulb, then off when you switch off that circuit. Brakes are an exception. If a brake bulb is bad, even intermittently, the warning light will stay on from when it first senses the bad bulb until you switch off the engine.

Sixto
87 300D

[sixto]

US 124s have a poor contact design for the side marker bulb in the tail light clusters.

Sixto
87 300D

[babymog]

x2 on that Dave. That pesky (sedan and coupe) side-marker has cost me a few bulb-holder replacements.