1977 240D Door Switch

[mchaix]

I have a 1977 240D and the drivers side front door has two switches the top one operates the front dome lite. I can't find what the one on the bottom operates. can anyone help me with this? I have attached a picture of the switches. thanks in advance.
Mitch

[gmog220d]

One switch is for the dome light. The other must be for the warning buzzer that sounds when you open the door without removing the key from the ign. switch, and perhaps also when you leave the lights on.

[MagicBus]

Originally Posted by gmog220d

One switch is for the dome light. The other must be for the warning buzzer that sounds when you open the door without removing the key from the ign. switch, and perhaps also when you leave the lights on.

I'm not familiar with the wiring in THAT early a 240D, but in the later cars, at least, a single contact switch handles the lights/buzzer.

If I had to guess... this is a 38 year old car, and I'd bet that the second switch was for an alarm system that may or may not still be (at least partially) installed.

[gmog220d]

That 2nd switch is in my '74, was in a '76 I parted out too, and is probably in the '73. Now I'm really curious . . .

Dug into the wiring diagrams. It shows two switches, RH and LH for the "courtesy light", and a separate single switch for the warning buzzer. The circuits for each system are independent. The diagram notes that the buzzer's switch is the upper switch in the LH door opening (US market). Guess yours (OP's) got swapped between positions at some point.

Perhaps Benz added the buzzer circuit to an already established wiring scheme without a complete redesign of that part of the system.