The two a/c vents for the driver's side on my Nissan Pathfinder are blowing luke-warm to cool air while the passengers vents and the rear vents are blowing cold air. We asked the parts guy at our local Nissan dealer and he said it could be one of many sensors. We have already checked the freon level with the rechargeable cans with gauge on it. And it was fully charged. We also compared the charge to another vehicle to make sure the can was working. Any suggestions before we have to take it to the dealer and pay $100/hr to diagnose? Thanks, Sonia