Car wont blow any air
More than likely it would be the blower motor resistor that is bad.
Before the manufacturers started installing cab filters, all sorts of foreign matter collected on the front of the evaporator. Pollen, animal hair etc collect and cut the flow thru the evaporator. I do not know your car that well so you may need to do some investigation on how to get to it so you can clean the front. You might get to it via the blower motor hole....use a shop vac and suck the junk off the front.....
the attached photo is the evaporator in a late Riviera (up to 93)
Looking for a Used Century in your area?
CarGurus has 17 nationwide Century listings and the tools to find you a great deal.
Search Buick Century Questions
Buick Century Experts
Related Models For Sale