Auto Air Conditioning & Heater Repair: 98 Altima A/C Blows Hot air, fan assemblies, autozone

Question
My car is only blowing hot air, I bought one of those Freon Kits from AutoZone and measured the pressure according to the table on the side of the can it was okay at 55 PSI. Also how do I know when my clutch is engaging? Am I supposed to hear a change in engine? or look for a part to be moving? Thanks.

Answer
The clutch is located at the compressor.  Compressor is the bottom pulley towards the front of the engine.  Between engine and fan assemblies.  Look at the front and see if it engages.  Also with ac off your pressures should be 80 to 100 psi and when ac engages it will come down.  If it does not engage you may just be too low on refrigerant at engage comp.