I have a 04 Mercury Sable LS, Duratec engine, V6. I knew it needed a new ac compressor and freon. I have the ac set on auto and have switched back to manual many times, set on recirculate. I live 5 miles from the entrance of nasa in Florida. So it's always hot and humid here. It blows cold when you put your hand up to the vent. It blows strong, but it's not cooling down inside the car. The car is silver so it's not absorbing heat from the sun. The ac hoses looked good. My mechanic said I shouldn't have to change them. There are no leaks. What could the issue be? I know there is a filter under the cowl on the passenger side, but I don't believe that had anything to do with it. Since, from my understanding it's to filter dust and such from the cab. I know this is a specialty engine. I'm wondering if there is another part or two that I don't know about that could possibly change to help remedy the situation. If you have any ideas is really appreciate it. I'd like to fix it myself without having to go back to my mechanic on Monday.