A/C has a mind of its own!

[NickRanger89]

So...my a/c has a mind of his own so to say. When ever it feels like it, it switchs from blowing out of the vents to the defroster. Maybe every minute or so, I have to let go of the gas, let the rpms fully drop then blows back out the vents. I assume there is some kind of vaccum leak? The clutch on the compressor also clicks every 20 sec or so. The a/c sweats ALOT aswell. All of the air speeds work correctly, all the selectors and indicators work but there is little to no diffrence between a/c and max a/c, and it blows pretty cold, I mean I've felt colder but hey I'm not complaning here in Florida's summer. Its just a pain in the butt to let go of the gas all the time, also kills my gas milage on and off the gas. Any ideas?

 

[NickRanger89]

Its also on a 2.5 if that helps

 

[v8318cid]

What you're describing definitely sounds like a vacuum leak. The vent selector is powered by vacuum and when low, the actuators that direct air between the vents, floor and defrost (as well as the recirculation door/heater control valve if equipped) will not work properly. I believe the default location is defrost so you're probably noticing air flow only at the windshield when vacuum levels drop. As for the A/C system itself, sounds like it is working correctly. While sweating isn't a 100% gauge, it is a good indicator that the system has a proper charge. If you fix your vacuum problem, the A/C may work better when in MAX A/C mode since the heater control valve (if equipped) will shut off coolant flow to the heater core (less heat for the A/C to absorb). Check near the firewall for vacuum lines that may be loose or have broken off.

 

[Earl43P]

There is a vacuum reservoir.
Its input vacuum tube plugs into a check valve fitting on the reservoir.

They vary in location and shape.
My 2 93's had a torpedo shaped plastic reservoir atop the heater box in the engine compartment.

My 2000's was a black plastic sphere mounted to the PS fender liner, under the airbox.

It could be cracked, line cracked, check valve bad (available in the help section) or it is simply an engine vacuum leak not supplying the reservoir. A short visual inspection should find the problem.