AC not blowing cold

Start at the fuses and clutch relay. The clutch fuse and EGR fuses power the relay. Test the clutch itself as well. Also look at the wiring to the clutch as it grounds to the block and the wire may have corroded off.

Then check the triple pressure switch. If either section of that fails the power to the clutch is cut off. Next check the interior controls.
Do you have a good scan tool that can trigger the clutch? That makes it a lot easier to deal with this system as the clutch is controlled through the PCM and the tool would allow you to check the controls as you select AC.