I have an 03 Chevy blazer and when I try to put on theheat it comes out of all the vents tthe defrost the middle and the floor so it is weaker since the fan isn't going to one vent and winter iscoming up so Iwould like to have the defrost working pproperly does anyone know what it could be when Ihave it off it still ccomes out the middle (more air the faster I'mgoing ) iI can hear air from right behind the dash like it is trying to switch but its not my mech changed some of the vacuum tubes but it didn't work (he didn't charge me) could it possibly be the actuator?

 

Sounds like the usual blend door actuator.

 

richphotos;605537]Sounds like the usual blend door actuator.[/QUOTE]

That's the thing that's a pain in the *** to get to behind the glove box right?

 

I am not sure where it is on a second gen to be honest.

 

I ordered a new one and I will try and replace it and if it
I'll let you know