W123 vacuum door lock mod- anyone done this?
 

I don't want all the doors and trunk to unlock when I unlock the drivers door. I want a separate action, i.e. using an elec. or mechanical vacuum switch to open the other doors and truck only when I want to. Has anyone done this to their W123 and how did you do it?

Haven't, but it would be very simple.

The other doors and trunk etc. are simply controlled by pulling and pushing on this so-called master vacuum switch (red arrow, pointing down for those red/green colorblind!):

http://i.imgur.com/V9z2AIh.png

In order to "disable" the factory function of everything unlocking you simply need to remove the linkage (green arrow, pointing up).

As that point, you can unlock the driver's door and nothing else will unlock.

Then just re-locate this switch, modify (shorten/lengthen) the three hard vacuum lines as needed, and install a push/pull solenoid. This could be wired to a switch. Or you can undoubtedly find a way to connect it to a remote control.

I would probably consider mounting that switch down on the lower door sill, around where you find the vacuum actuators on the other doors. Would make for easy access, and would require shortening the hard lines instead of making them longer which just strikes me as easier in the long run.

Actually, would be kind of neat to also install an electric actuator for the driver's door that was controlled by a remote. You could then set it up like a "modern" keyless entry. One button push would trigger the electric actuator and open the driver's door. A different button, or a double click on the main button, and the solenoid would kick in and unlock the rest of the doors. Locking, hopefully you could make it so one button push triggered both the electric actuator and the solenoid to lock everything.

Anyway, that's one idea. Go forth and make a DIY guide for the rest of us! :D

I did this on my 83 300D a few years back. It is a piece of cake.

why?

Are you still using vacuum for everything but the driver's door, or have you gone full electric?

I installed an actuator to pull/push the vacuum switch. It takes a bit of doing to locate and mount the actuator by the dr/door but the rest is pretty simple.

What kind of actuator did you use? Pics?

Hook it up to the vacuum switch at the driver's door. The keyless remote control unit is configurated like a normal 12v pulse to open and reverse the voltage to close - just like any electric control modern car. Do NOT configure it as pneumatic control. Picture attached, pretty standard actuator.