Good morning to all. Started my 2000 Blazer this morning [-15C]and turned heater controls to defrost I heard a loud snap noise at first I thought it was the windshield. After it warmed up I noticed I have no air flow to floor outlet. All other postions are working fine. When I put the control to floor postion all air comes out of defrost postion? I wondered if anyone has had a similiar problem? I also wanted to thank everyone on this Forum for all their great help with my Blazer.

 

Sounds like you have broken the actuator that controls the defrost/floor door.

 

Thanks Kyle
I think you are right. I took of a cover off under the dash I see a white plastic arm hooked to the actuator its moving
but it seems really sloppy-likely broke inside. At first glance it looks like half the dash has to be pulled to repair. I guess I,ll being driving with cold feet...Jamie