If it was myself I would have to say it is entirely possible for me to hook the Vacuum Lines in the wrong place; unless I had drawn a picture or taken a photo of it before I removed it.
It is also possible that when you removed it that a Line got yanked and disconnected somewhere un-seen.

__________________
84 300D, 82 Volvo 244Gl Diesel

Looking in the "Ofishial" FSM for the W123. section 80-020

There are 3 lines running to the vacuum switch on the drivers door.
Suction line to vacuum switch (27).....Yellow
Interlocking line (25).........................Yellow-red
Unlocking line (26)...........................Yellow-green

The left side the slider is on is #25
Center is #27
Right #26


Installation

Connect vacuum switch to door lock

Attach vacuum switch with oval head screws
in such a manner that switch will be hard to move
within is`s oblong holes.

Slip connections (rubber hoses) with interlocking line (25)
unlocking line (26) and suction line (27) on vacuum
switch.

Run engine for a short moment, insert door key
into lock and open and close.

Note: Central interlock should already respond before
the key is at it`s respective end position.

Adjust plastic vacuum switch in such a manner that
the outer edge of the switch in unlocked condition
(in sedans) or in locked condition (in coupes) is in
alignment with center of adjusting groove.

Looks like in the drawing, the groove in the slider has to be lined up with the edge of the switch body.

Attention!
if the adjusting range is inadequate, extend oblong
holes (slots) in holder by filing.

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

thanks guys! I do indeed have a mighty vac, and confirmed the problem is the master switch. doorlocks were working fine one day and had been for years, and the next day I had a run-on engine.

I'll tinker around a little, but thanks so much for the hose arrangement info.