Chevrolet Repair: Cobalt, chevy cobalt, compressor clutch

Question
I have a 2008 Chevy Cobalt 2.2L. Early this spring, the a/c began going in and out while driving as far as cooling, it blows fine. Sometimes when it was not working the check engine light would come on and there would be know coolant reading on the dash. I took it to the dealership and they said it was two separate issues. They said the freon was a pound low, but the reason the check engine light was on was from a bad thermostat. I had them replace the thermostat, they said they cleared the code but a mile down the road the light came back on. I took it to a lube shop to have the freon charged at a cheaper price, and their mechanic said that the freon level was fine but the coolant sensor needed replaced. After it was replaced the light stayed off and the a/c worked just fine. That was in May, last week the a/c started not cooling on and off again. So far no lights have come on yet. Any ideas? Thanks

Answer
GOOD MORN TAYLOR, DO YOU KNOW WHAT THE A/C COMPRESSOR LOOKS LIKE ?? IF SO I WOULD LIKE YOU TO HAVE SOMEONE IN THE CAR AND YOU LOOKING AT THE COMPRESSOR HAVE THEM TURN THE A/C ON AND WATCH AND SEE IF THE FRONT OF THE COMPRESSOR [CLUTCH AND HUB ASSEMBLY] TURN WITH THE PULLEY WHEN THE CLUTCH IS ENGAGED A/C TURNED ON.MAY NEED A FLASHLIGHT TO SEE. IF SO THEN YOU KNOW THE COMPRESSOR IS WORKING AND RECEIVING THE SIGNAL FROM THE SWITCH AND BCM [BODY CONTROL MODULE] TO DO SO..SO IF IT DOES TURN ON IT SOUNDS LIKE THE FREON IS LOW..YOU MAY HAVE A SMALL LEAK CAUSING THE FREON TO BLEED OUT OF THE SYSTEM..YOU WILL NEED TO TAKE IT TO A SHOP AND HAVE THEM CK IT FOR LEAKS WITH A DYE THAT THEY WILL INSTALL IN THE SYSTEM..BUT LETS SAY THE THE A/C COMPRESSOR TURNS ON AND THEN OFF REAL FAST THIS STILL IS A SIGN THAT THE FREON IS LOW ,BUT NOT LOW ENOUGH TO NOT TURN THE COMPRESSOR ON..
IF YOU HAVE THIS CHECKED AND THE FREON IS FULL AND THE COMPRESSOR WILL NOT TURN ON THIS IS A SIGNAL PROBLEM,SUCH AS WIRING FAULT,SWITCH,FAULTY BCM..YOU GET THE IDEA...IF YOU KNOW OF SOMEONE WITH A/C GAUGES YOU COULD HAVE THEM HOOK THEM UP TO YOUR SYSTEM AND THEY COULD TELL HOW MUCH FREON WAS IN THE SYSTEM...THERE ARE MANY AREAS WHERE FREON COULD START LEAKING OUT...THIS WILL BE HARD FOR YOU TO DIAGNOSE WITH NO TOOLS..SO IF THE COMPRESSOR DOES TURN ON AND CYCLE'S OFF RIGHT AWAY THE SYSTEM IS FOR SURE LOW. THE FACT THE THE CK ENG LIGHT HAS NOT COME ON TELLS ME THAT THE SYSTEM IS MORE THEN LIKELY OK ..THE SYSTEM WILL NOT SET A CODE FOR LOW OR EMPTY FREON.
JUST SOMETHING MECHANICAL... I HOPE THIS HELPS YOU OR IF YOU NEED MORE INFO GET BACK TO ME AND GOOD LUCK,,TOM