mpace

The OEM LED tail lights on my 350 GLK do not completly illuminate. It clearly has two Lighted Areas, Both Outlines work with running lights on. But only the top section of the tail lights light up when braking.

There is no situation that I ever see the lower light on. Not wen Braking, turn signals, hazzord, fog light... When do these lights work? Why are they there?

MBKLUE

Have you tried it with the headlights on LOW BEAM (try not using Auto mode) and the rear fog light switch depressed (switch to the left of the rotary headlight knob)?

formerjeepguy

Does this help?

https://mbworld.org/forums/glk-class...gnal-rear.html

mpace

Yes, that link completely answered my question. Thank you!