W124 bulb warning light but all lights work. I was getting my car ready for inspection and I replaced several bulbs. Is it possible that non OEM bulbs will trip the bulb warning light? no big deal but if I ever want to sell my 300D it's looks a lot better when I can say "everything works"

__________________
1993 MB 300D 245K died.

Check the wattage value of the rear lights. I think it is common to fit 2.5W rather 5W (or vice versa, I forget) for either the tail lights or the brake lights (I also forget).

Take them out and compare to the owners manual, and change them for the correct wattage if necessary.

__________________
1991 W124 250D - 130k Miles

Common missed light is the license plate light(s).
Also, I've had several of these light fail relays die on me.

It's the long one just behind the fusebox. You need to remove some phillips head screws to get to the relay portion of the fusebox.

Jim

__________________
14 E250 BlueTEC black. 45k miles
95 E320 Cabriolet Emerald green 66k miles
94 E320 Cabriolet Emerald green 152k miles
85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles

Well-meaning folks often put in larger bulbs that burn up one of the dropping resistors in the lamp-fail module. Because some of these bulbs in various wattages appear identical, you have to read the fine print. Once the module has been damaged it will never work properly.

The photo shows one such damaged module due to using 10W license-plate lamps instead of the spec'd 5W. The serpentine metal pieces are very-low-resistance dropping resistors the module uses to sense whether current is being drawn; if the amount doesn't correspond to design values, the warning light illuminates. A fried resistor does the same trick.

Jeremy

EDIT: Typo in the photo, part number should be 126-542-01-32.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

the license plate lights are working, the area I was working was the tail lights so that is were I'm going next. if I smoked the module I'll just live with it.

__________________
1993 MB 300D 245K died.

Same thing happened to me after soldering in new headlight sockets, it's been on since. Unfortunate feature to lose, ain't it?

I think those modules are pretty easy to come by, found ~3 at a yard just the other day.

The lamp-fail module appears to be common to most all 124s and some 126s.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I think I might go with electrician's tape fix. just tape over the light

__________________
1993 MB 300D 245K died.

I would double check the connections on all of your tail lights. I remember seeing someone post about the sockets in the rear assembly can corrode a bit with age and cause issues with the light out warning system.

Drago.
Your next step is isolating the lights causing he problem. For instance, with the engine idling does the lamp out light come on when you turn on the parking lights with all others off (foot off brakes, headlights off, etc)? If it does, it is in the parking light system. If it doesn't come on, then turn them off and put your foot on the brakes. Light comes on, brake light problem. Then try turn signals. Headlights? I/m sure you get the idea.
Once you narrow it down, turn all lights off except the system causing the lamp out to come on. Look VERY carefully at each light looking for one light dimmer than the corresponding light on the other side of the car. For instance, lets say that the problem is with the parking lights. Look at the parking light on the left rear and the right rear and see if they look exactly the same in brightness (as closes as you can). If they look the same then look at the right front and left front, etc. If one is dim and the other is bright then you probably found the results of the problem, so you know the cause can't be far away. Check the two bulbs and make sure they are the same. Also check all side markers and tag lights.
This is an old trick we used at our shop when someone came in with a problem like yours. We usually could find and fix the problem in the parking lot and have a customer for life.
Of course there are a lot of other problems you could have but the above usually fixes this type of problem. But if you can narrow it down some, it will make the fix a lot easer.

PaulM

__________________
84 500 SEL (307,xxx miles)