97 grand voyager - ac problems

The AC in my voyager is cold on the passenger side but not the driver side. Is there somekind of baffel or other mechanism that could be stinking and staying closed and not allow the colder air to come out on the driver side? The van is equiped with the dual temp controls for the driver/passenger.

Occassionally i hear some hissing noise under the passenger side dashboard while the AC is on and the temp control on cold.

thanks in advance