HOLD ON !!! I had the same symptom when I bought a truck and turns out it had TOO MUCH Freon in it. Somebody overcharged it trying to solve the above problem. Have it gauged BEFORE you charge it so you don't mess something up. Most of the time this is happening on higher-mileage trucks with the original compressor and clutch with a worn disc. Solution? You can replace the clutch, the compressor and clutch assembly, OR (what I did ) get a little more out of the original by loosening the belt and taking t off the top pulley, move the coolant recovery tank out of the way, remove the small bolt on the a/c clutch center and then the outer clutch assembly. Remove the small spacer washer (about the size of a dime), and possibly use a file or Dremel to remove about the same amount of material from the end of the bolt, then reassemble. Did mine two years ago, and I still have nice cold air. All this does is compensate for wear in the magnetically-attracted clutch disc, and buy maybe another 200 thousand miles before the clutch should be replaced !!!