What Is This?
 

After soldering my cruise control amp on the 560SEL and reinstalling it, I thought I was being clever by cutting the wire up there on what I assumed was that super annoying seatbelt buzzer from hell. To my amazement, the buzzer still works and continues to annoy me. What is this small round bluish component under the dash that I cut the wire to? Nothing seems broken. - Mike

PS - Cruise control works great now.

Attachment 147409

Possibly the cabin microphone for an aftermarket alarm system.

Sixto
98 E320s sedan and wagon

LOL @ randomly cutting unidentified wires !! Almost looks as if you could have undone a connection? No clue what that is.

Why would you cut a wire, any wire - much less one you're unsure what it is, when there's a connector one cm away that could have been unplugged?

Hey now...
 

I was so sure it was that stupid buzzer. Lesson learned.

I disabled my W201 seatbelt buzzer by unplugging a red harness under the front of the driver seat. Perhaps yours is the same. Buzzer still works as a headlight and key reminder.