Great pictures...you ought to write a shop manual.
I believe the 4 pin plug above the vacuum lines is for controlling the A/C.
It may say in the owners manual. A lot of vehicles now automatically turn on the A/C compressor when you chose Defrost.
I just noticed the off position in the airflow control. Those pins may simply be to shut off the fan also.
Some also have a min fan speed for having the A/C engaged, like medium or something. That may be what the other pins are for.
That rheostat for controlling the temp is neat, that should be easy to control with a circuit (but don't ask me what kind)
[This message has been edited by DodgeCummins (edited 03-24-2001).]
/me blushes thanks dodge.
plaiming2 not sure see what you think after reading this.
As always remember IANAW(I Am Not an Auto Worker)
ok the four wires from the output control go like this (not sure of the numbers for each one because I am not at my car right now but this will at least give you a better idea I hope.
one of them if you are in Max A/C, A/C, Def/Flr, Defrost it goes to the A/C clutch Relay I would guess to turn it on.
One of the other wires from the four I am not completely sure what it does but it will do whatever it is when the switch is not in the off position.
Now again based on my interpertation of the diagram it looks like there might be 2 wires that does something in the off position one of them seems to go to the Air Temperature Actuator that the temp switch goes into (this could just be power since it also has a 15A fuse on it and the other one seems like it might connect to Heater blower motor