Anyone worked on these on a 83 300d? Symtoms started this week. Center vents would start blowing with AC if you started the system from off. After a few minutes no air from center vents and the car will take about 5 seconds to shut off with air on. I figured I had either a bad push button unit or a bad unit that pushes all the levers behind the dash. PBU was swapped with a known good one with no change. Pink things under left side seem to be ok and I can't hear any loss of vacuum behind the dash.
So I started to unplug the vacuum switches behind the PBU. With number 5 counting left to right unplugged I get good air from the center vents and side plus the floor. On defrost I get good air up top and on the sides, nothing from the center. On heat I get warm air from the same as when the AC is on. Car shuts off instantly with system running. So is my problem in the #5 switch or is it a leak somewhere else.