Air conditioner blows hot air when outside temperature is above eighty degrees

Thank you, tried the fuse thing, nothing seemed to change. The actuator seems to change the vents from floor to vent to defrost just fine if that is what that is about. It is seventy five degrees this morning and the conditioner works fine. Yesterday on the way back from the coast it was ninety five degrees and it would not blow cold or cool at all. The vents changed though because I turned the heater on to displace engine temp when at one point the heat gauge went up. The heater lowing hot air seemed to dissipate the hot air and cooled the engine. The actuator worked as I moved from floor to vent to defrost. The fan control did not seem to work on low or # 2 but worked on #3 setting and high. Strange. It used to work on the lower settings. Could it be something in a computer control module? Can that be tested for the conditioner portion for problems? Thanks for help.