Keyless Entry Wiring Key (W126,W123,ETC)

[JamesDean]

Hey everyone, I just wrapped up an install on my dad's SD so I figured I'd share my experience and maybe help someone out.



I used a fairly cheap unit, Avital 2101L, I paid $28 for it. In my particular application (82 300SD) I needed to install an acutator to drive the front door lock as Mercedes didnt equip the early w126s with vaccum abilities at this door. As I was poking around in there I swear I saw a vacuum nipple so perhaps one could just run a vac line to it and it would work. I didnt try though. You'll want to get a high-power/high torque actuator for the door lock. I bought a cheapy $3 when I got the Avital unit however it was inadequate. I ended up buying one locally that did the job excellently.

Heres the simple rundown:

1) I installed the control unit in the second firewall area just next to the brake booster assembly.

2) I ran all the necessary wires into the cabin using the hood-release cable grommet.

3) I used some steel cable to fish the two wires for the actuator through the accordions in the door jamb. I had a third wire tap the top door check switch in order to activate the dome light when the unlock button is pressed.

4) The actuator was mounted to the lower outside area of the door and then the rod was connected to the vertical lock rod.

5) I wired up the controller as indicated in the image below. I havent done the parking/horn connections yet as its pretty cold outside but other than that it works!



If anyone has any questions or comments, let me know. I'll be happy to answer.