I have a 2010 Chevy impala ls and last month is was unbearably hot here, over 80 each day. I went to use the ac and noticed that it was running slightly cool not as cold as it use to be. Then all the sudden it just shuts off. I try to turn it on again and nothing. Next day i buy freon and put a whole can in there, small short can, knowing that it had never had a charge put into it. assuming this would solve the problem and again same thing it runs for awhile then shuts off and wont come back on until i start driving but if i come to a long stop or in stop and go traffic it shuts off. the last time i tried it was the following day and nothing. It wont turn on at all and now the light just blinks then off and if i run the front defrost it now make a weird humming noise and the ac light on the button blinks. I am so lost anyone have any ideas of what the heck it could be?

 

Your system needs a thorough troubleshooting. Adding a can isn't going to fix it, it's only going to destroy your compressor. If there isn't enough refrigerant in the system, it will shut itself down to avoid damage. you have a nice leak somewhere.

 

Take it to a shop and have them put a dye charge in it and check it for leaks with a uv light.