A/C & Heater issue - Takes 15+ minutes to finally kick on
 

Hi, I'm having issues with my stock MT 06 350z with 31K miles. The issue started last winter and now has become close to unbearable now that it is summer. The AC/heater seems to take a significant amount of time (15+ minutes) to finally kick on while driving not matter what the setting. Also, while in motion, i can feel small amounts of cold air coming through when the middle AC switch is set to 'through'. Now eventually the heat/cold air will function like normal and i can start the car up again later and only have to wait a couple minutes if any to get full air. I have confirmed that both radiator fans are spinning. Any idea on whats going on here?

Thanks