Heater problems 2003 Cavy

Hey guys, If anyone could help me with this it would be awesome.

I have a 2003 Chevy Cavalier, which I just bought recently. Love it to bits, but tonight I encountered a problem:disappoin

My heater is working but when I try to turn the vent knob, it doesn't want to turn. The setting is at the front vents, but if I want to have the floor or window vents working, it won't turn over. You can feel the knob not wanting to turn, like a spring action agianst it. And the green light usually goes on to tell me that the air is coming out, but it doesn't. When I try to turn it I can hear something try to work, a buzzing noise. Im guessing it's my Louvers won't turn, since the air just comes out the front, but how do I fix it?

And btw, Im trying to make my Cavy, customized, and was wondering if there are Any altezza, or any different tail lights for 2003+ Cavys. I've been searching but can't find any really cool modifications, which is sad. So any help with both, mainly the first one, would be great!

Thanks a lot guys!