a/c compressor shuts off on hot days or nights only. runs good on fresh days or nights.already did vacum and added fresh freon. still problem presists

one mechanic said just needs freon , the other said its your compressor

 

How are the "mechanics" determining this? Anyone put a set of gauges in it and verify the pressures are good?

 

one of them is a certified a/c repair shop. but i dought his jugement. becouse of the fact that he said be ready in an hour went by his shop 2h later and he looked scared like he didnt even check the vehicle. he said needs freon, took it to another certifide a/c said lets do a vacum and only add what it need. but that didnt change a thing it started for like 1/2 a min then stoped and with out looking back at the guages he said it was the compressor.. he said it was too week, i went and looked it wasnt engaged, he argued that it was engaged... thats when i told him off and gave him a pice of mi mind

 

electric fans work properly, engine temp never above normal,i looked up simillar issues and some say its a ambient sensor issue, now i dont have a tool to test the ambient senssor, and the worst thing is i cant seem to find the sensor or even the wire that connects it, most of the time its conected under or near the front bumper but i found nothing i took the entire front end apart and found nothing