[rwin1592]

What controls the cycle of the A/C compressor on my '67 with factory air. I don't see any switch associated with the heat/cool slide control. Does it run any time the fan switch is calling for the blower then the temperature is mixed by the door that moves with the heat/cool slide??

 

[Coppertop]

There is no "cycling" in original Chevelle A/C's. The compressor clutch is engaged and turning whenever the A/C is on. The POA valve is what controls consistant temp via pressure regulating I believe. The series of cables and vacuum lines open doors to direct air to the proper vents and mix incoming air for a proper temp, but nothing "regulates" other than the person at the controls.

 

[Coppertop]

Ooops, I kinda re-read your question...

The A/C compressor is only activated in A/C mode or defrost. On my '70, there's a little leaf switch that gets closed when you slide the control to the above positions sending power out to the compressor's clutch.

 

[meesh]

On my 67, you can set the controls to A/C (cool) but the compressor will not start until you turn on the fan. I know this becasue of the idel change. Seems wierd but that is how is works and I replaced the A/C wiring so I believe I have it right.

I haven't tired it with the defroster on but I will now.....