A/C Issues STILL ONGOING

Thank You everyone for the feedback. As I said this is has been an ongoing annoyance over many years. The truck has been to 2 seperate chevy dealers, 2 firestone service centers several times, a repair shop that specializes in trucks, and from all the invoices it appears that every part of the a/c unit has been replaced. The last mechanic to work on it, swore he had it fixed and claimed that he drove it out and thru the city and it worked fine. BS! I appreciate the comments. Will be discussing this with the mechanics at a new shop in hopes that we can come to final diagnosis, repair.