OK, here's a listing of the vacuum lines and vacuum block connections for the 124. The #1 connection is the top of the vacuum block, #7 is the bottom.

#1) Fresh air/Recirculated air flap small lift. Line color is dark red. When activated, this line moves the recirculated air flap from the 80% recirculated (i.e. mostly closed) position to the 100% recirculated (fully closed) position. With the glove box removed, you can actually see part of this flap, directly in front of the heater box, up against the firewall. This port on the vacuum block is activated with pushbutton "0" (i.e. off) pushed.

#2) Fresh air/Recirculated air flap large lift. Line color is medium green/light blue. When activated, this line moves the recirculated air flap from the open position to the 80% recirculated (mostly closed) position. With the glove box removed, you can actually see part of this flap, directly in front of the heater box, up against the firewall. This port on the vacuum block is activated with pushbutton 0 pushed.

#3) Footwell flaps. Line color is red/yellow. When activated, opens the flootwell flaps. This port is activated with the hilo pushbutton.

#4) Center dash vent flap. Line color is red/black. When activated, this line opens the center dash vents. The vacuum port is activated with the "EC" pushbutton selected and the temp wheel rotated to the min position.

#5) Defroster vents large lift. Line color is red/white. The defroster vents are normally fully open. When this line is activated, it closes the defoster vents most of the way, leaving a bit of air to leak out the defrost vents. The vacuum port is activated with the "EC" pushbutton selected and the temp wheel rotated to the min position.

#6) Diverter valve flap. Line color is medium green. See previous discussions in this thread for the function of the diverter flap. The diverter flap is normally closed, applying vacuum opens it. The vacuum port is activated with the EC pushbutton selected and the temp wheel rotated to the min position.

#7) Defroster vents small lift. Line color is red/light blue. This line takes the defroster vents from mostly closed (see #5 above) to completely closed. The vacuum port is activated with the "EC" pushbutton selected and the temp wheel rotated to the min position. On my car, it seems to leave this port unactivated for the first 30 seconds after starting the car, thus directing a little bit of air to the windshield. Then this one port is activated, completely closing the defrost vents.

- JimY