To properly perform all the ACC circuit tests, you need to get the ACC tech. manual from the dealer. It costs around $30 and gives the step by step procedures.

It sounds as though your recirculating air flap located to the rear of the glove box is malfunctioning. When the flap is fully forward toward the engine it is closed and does not allow outside air into the car. The two vacuum switches that control this flap are two stage like the one you replaced for the defrost. In the AC mode (button c in the middle of pushbutton) the flap should be about 3/16 on an inch from fully closed which is considered 80% recirculated air. The flap should move to 100% closed with the temp. dial set to minimum. In all other modes including economy mode (button d) the flap should be fully open toward the glove box. Hope this helps.