I had the burned out bulb indicator light, and I found they all worked.

And then it occured to me that I hadn't checked the 3rd brake light. You know, the one that is on the hat shelf mounted at the base of the rear window. This was the light that was burned out.

It is also a good idea to check the lights that illuminate the license plate.

I think some on this forum have had the burned out bulb indicator illuminate and all the bulbs worked. Perhaps using aftermarket bulbs don't put out the correct wattage that the system is looking for.

If all your bulbs are fine, then I'd systematically replace them with OE bulbs from the dealer.

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".