I have a 2004 Silverado ext cab, all air HOT and COLD blows out through the defrost only, which actuator it it??? thanks

 

Mode actuator

 

Blend door actuator I think is what it's called? I had to replace it on a few trucks. There's 2 for sure and have read there's a third but i don't know where it's at. The 2 I've replaced are on each side, on up under the glovebox area, and the other is under the kick panel on the driver side to the right of the steering wheel. Kind of a pain to get to, they're held on by 2 screws. 7mm, have fun!