The compressor clicks on when a/c is on and the idle is adjusted as it should. It has charge in it, but it blows hot air.

I turn the controls to hot just to make sure that the control is working and it gets hotter so it does, but the air is still hot. I went under the hood and pulled the cable that's attach to the temp control all the way shut so the cold air should come through, but it didn't work. Can someone help me out on this one?