Out of the blue my AC stopped cooling. The blower is still strong, but at idle the air is warm and while on the gas the air gets slightly cooler. The compressor is engaged but does make a rattling noise that goes away if the AC is turned off. The condenser does not get cold or have any condensation on it. I was able to check the PSI on the low side and it is reading over 80. Any ideas?

 

A/C set to MAX, blower on high speed, windows & doors closed, engine ~1500 rpm:

Does the compressor cycle on and off?
Is it on or off continuously?
Next we need to know the cycling pressures:
What is low side pressure when the compressor turns on?
What is low side pressure when the compressor shuts off?
What is high side pressure just before the compressor shuts off?
What is the ambient temperature?
What is the relative humidity?

Low side pressure should never reach 80psi while the compressor is on.
The condenser is in front of the radiator and should NEVER get cold. If it does, there is a restriction in the condenser where it changes from hot to cold.