I have a 93 Olds 98 supercharged touring sedan, I've had trouble with the A/C, When I put it at 60 degrees and the fan on high nothing blows out the left or right vent, one center vent blows a little, sometimes cold sometimes just regular air, the other center vent weakly blows hot air

There'* a blend actuator located behind the glovebox. A common failure problem, and easily replaced. This may be your issue.