A/C blowing hot air

2004 ford explorer a/c blowing hot air when in idle or parked at times will flucuate from hot to not as hot but not cold and when it does kick in the air smells wet. A/c will cool when in motion but it is not as cold nor does it blow as hard as when I first purched it. Have had the compressor replaced last summer the blend doors a few months ago the thermostat last week replaced fluid in radiator 50/50 when changed the thermosat checked charge on a/c and it reads that it is charged. Need help badly. I live in az and it's getting hot but still cooler outside the car than inside of it with the ac on high.