[hmmpepsi]

Bob, I have a 1990 lumina apv. I had the same problem twice now. Replace the Blower motor. It is attached to the fire wall. Open hood and it is next to the windshield wiper motor on the drivers side. removed the air cleaner assembly. You may have to remove the left side windshield wiper arm linkage. I am pretty sure that you do. You may be able to use the old fan. Sometimes the fan is to brittle and you may break it upon removal. I would recommend purchasing the dealers blower motor, it comes as an assembly motor and blower. autozone and checket only sells the motor but, your fan may break.
If you already check all fuses and realay then I am pretty sure its the motor. I replace mine twice now, but my lumina is 19 years old.