My car has A/C problems on the passenger side only.

I turn on the A/C and it blows cold air on driver side only and half of the middle vents.

The right vent in the middle and passenger side vent stays hot.

Yes I know there's a dual button and it doesn't make a difference.

I've had this car for over 2 years and never had this problem before.

HELP!

 

I think this may be the infamous servo problems. Do some searching on your symptoms, there are a lot of threads about this problem.