I have the same car, mine does the exact opposite tho, short-cycles at idle, then gets good & cold at speed. I'm thinking since I've recently added two 12oz cans the pressure may be too high at idle. it even short-cycles if i'm sitting still and raise the rpm's. but when I get going, it kicks in and stays engaged & gets good and cold... what is proper pressure reading.???? where is pressure sensor?

check the relays for the AC and just replace the current fuse with a new one don't asked why but it worked for me.

You didn't say how the "reputable" charlies checked/replaced your freon. Did they evacuate and then refill the system with 1.6 lbs of refrigerant, or did they guess and just stick some more in? What pressure readings did you see when they tested the system ?

To me it sounds like you have too much refrigerant, the pressure is too high, and system is icing up, If you leave it for a while, the ice melts, and the system works again.

I'd take it back, and compalin.

RC

What does the "very reputable" AC shop say then? If it's fully charged and they've taken your money, they should then be able to properly diagnose your AC concern, right? If the freon charge is correct, the evap (even if slowly leaking) isn't the cause of why you're now still having problems so don't let them replace your evap now because of this.
If it's fully charged (and there's no doubt) then I'd check pressure switches (2) and if it's doing this with a hot engine and the temp guage reads higher than normal, a sticking thermostat (sticking closed) will cause the fuel ECU to shut the AC off (not common however).

1995 850 turbo wagon here. Ours does the exact same thing. Our AC is fully charged, but after driving for a little while, suddenly the air will blow warm. But that's not the weird part...

Weird part #1: When it starts to blow warm, if I turn the blower switch to "0" position, the residual air coming out of the vents is ice cold. As soon as I turn the fan back on to any position, the air starts out cold, then immediately turns warm again. I can hear some kind of slow steady clicking sound coming from behind the control unit. This is also a random thing.

Weird part #2: If I turn off the fan to the "0" position, sometimes the compressor will continue to turn. Sometimes it won't.

This is all really pissing me off. Let's not even mention that I have to recharge the bloody thing every month.

Looking for help.

kevin