2000 Cavalier -> Fan Speed Control

Hi, I have a 2000 Cavalier and the Fan Speed Controller used to work properly (at all four levels)....however, recently when i turn the fan speed controller to Level 1 or Level 2 (where Level 1 = Min, Level 4 = Max), nothing comes out...for all type of settings I tried (incl. AC). However, when i turn it to Level 3 or Level 4, it's cranked up to the MAX!!!

What is wrong with it? Is there a loose connection somewhere behind the instrument panel? If so, how can i fix it?

Thanks!

Bad blower motor resistor.