A/C not cooling

I have a 1997 hyndai Elantra 4 cyl milage is 172000 My A/C sytem is not cooling I checked the refrigerent level with a over the counter $9.00 gauge for checking refrigerant level the gauge reads in the blue fully charged I then checked the blend door and this was also operating properly it was opening and closing also my compressor turns on immidietly after pushing the A/C switch, the low pressure aluminum hose is very cold at the engine entering the engine firewall can you help me narrow down my problem and my vehicle does have 2 fans at the radiator how do I know which one is for the A/C system I would appreciate your guidance.
Thank you ?