...but blows cold when I'm parked and idling. I can't figure it out. I have a 94 f-150. It is a r-134 system. The mechanic who did the a/c in the first place can't figure it out. I've been back to him at least 5 times to no avail. I bought all new parts for it. He's absolutely clueless at this point. Has anyone had this problem before? Any thoughts would help.