The 93 has a passenger airbag rather than a glovebox. I've never looked up the procedure to remove it, but other than that the process to check the vacuum elements should be the same as for earlier cars. I'm going to double up on Larry's bet - probably a problem with the recirculate flap. It's likely you're cooling/dehumidifying only outside air. Works much better with 100% recirculated air - once all the moisture is out, it gets real cool...

Pull the airbag, then check all seven vacuum lines on the switchover valve. All should hold vacuum. Let us know which ones are leaking, and we'll let you know how much work you're looking at.

- JimY