The white vaccuum line is supply from the vaccuum pump. The two "switches" vent the vaccum from the line to the transmission so that the vaccuum signal mimics a gasoline engine, more or less.

What should happen is that the vaccuum applied to the modulator should be 14-16" with throttle closed, drop to 12" as soon as the throttle opens, then gradually drop to 0 or so at wide open throttle.

There was a posting a month or so ago with the correct diagram included, but I don't remember what it was, you will have to search -- try "vaccuum diagram".

I think your lines are wrong, too -- if I remember correctly, the white line has a Y in it, one end to the switches, the other to the tranny. There should be a little yellow plastic restriction in the line where it conncects to the main vaccuum supply. The black line is a vent line to the interior of the car (to prevent dirt from getting into the vaccuum pump). If you route the vaccuum supply through the switches, you may not get enough at the modulator. Check the diagram posted and see if it matches yours.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!