I've noticed when it is really hot, my AC doesn't work very well. But blows ice cold when not that hot. Found the problem. When I press the air recirculating button I notice nothing happens to the flaps for the fresh air/recirculating unit. What do I think the culprit is? I was looking at these diagrams on Clarks:
944 HVAC Operation and Malfunctions
There are 2 vacuum units on either side of unit. Also there is a solenoid on the passenger side of it. If both flaps are not shutting, I would think it may be the solenoid no? Is there an easy way to get to that? Any other thoughts??Thanks guys!!

 

check the heater control clip. they break off after time and even though the solenoid moves, it doesnt shut the flap because the clip came off the rod.

 

Cool. Will do. Location of control clip???

 

Looked at the arms by the flaps. Had my wife press the button on and off. Nothing activates or tries to move on the arms at all.



I'm thinking it is a power problem. The solenoid is #2 in the diagram...how do I get to this sucker? Is it under the driver foot well?






Or #3 in this pic. But it would be of for both to break no? I'm thinking it's the solenoid in the first pic.

 

Check the two diaphragms with a vacuum pump and see if they close. If not, it is either the solenoid, wiring or the A/C control unit. I am having the exact problem with my car too, but never have enough time to chase it down when I am home.

The solenoids are NLA from Porsche. I guess you could bypass the solenoids and connect the diaphragms to the vacuum source and always be in recirculation mode.

 

So, after a lot of testing, I almost gave up. But I started playing with the climate control ****.
I read somewhere that the fresh air recirculating system is dependent on the setting of the thermostat. Low and behold I turned the dial up to the midway point, pressed the fresh air recirculating button and the flaps shut!!!! Soooo happy. Why they don't shut at any point of the themostar settings is beyond me? The way the temperature control system is set up on this car is archaic anyway so it Is no surprise.