Volvo Repair: a/c, volvo 850 glt, temp gauge

Question
i recently filled my freon for my 1996 volvo 850 glt and i noticed that after about 15 mins or so of driving with the a/c on the temp. gauge for reading the temperature outside goes up and the a/c stops blowing out cold air. there is no leaks that i've seen through uv coloring so i dont think there is a leak. if you could help me i would really appreciate it. thank you

Answer
maybe the temp gauge sensor  is on wrong spot were it gets to hot and engine thinks it is overheating turnig your ac off  location of the sensor is in  front the radiator were it snaps to the air guide  or the  front bumuper and it needs to have good air flow if no air flow or close to radiator it gets to hot and ac turns off  to protect the engine from overheating
good luck  if you from chicago i can help you more