This is on a 03 blazer....

The switch that controls the fan direction quit working on me. It is the one on the far right, turns ac to face, feet, feet/defrost, etc...

I normally leave it on feet/defrost all the time....but I switched it to face because I just left the store and had milk and ice cream on my pass floor....so it was for good reason!

But now it won't switch to anything else?
If I turn it all the way to off, it does turn off though?

Im curious if this is an easy fix or am I gonna be screwed by taking out my dash??

There are a few wrecking yards I could get switch panels from, but I don't wanna just start replacing things not knowing??

Thanks for your answers ahead of time!

***ps....my other heater switches work fine...speed and temp controls....

 

This diagram is for manual HVAC systems, (not automatic climate control) and shows which vacuum actuator should have vacuum in each mode switch position. Check that each actuator operates when it should at the respective mode switch setting.

 

I've got this same problem. When I select "feet", I only get a breeze out of the defrost. All other modes work fine.

I evaluated unit 15 in the diagram and it appears to work properly. I removed it and did not see any evidence of ATF.

Where is the slave module located? Is this the module that directs the wind direction toward the feet?

Your help is GREATLY appreciated!

 

Follow the grey vacuum line from the mode valve, (#15) to the vacuum tee. One side of the tee goes to the selector switch, and the other goes to the slave actuator. #15 is a two position actuator. #18 directs airflow in the heater case to the mode valve. The grey vacuum line should have vacuum only in the OFF and HEAT positions of the selector switch.

 

Well, I've got the dash leaned forward (finally), but it hasn't afforded me any additional room than I had before. I've removed the suspected actuator & then read that it's likely not the actuator but the part the actuator moves (inside the heater box).
I'm not quite sure how to access this part - am I supposed to completely remove the dash?

 

I pulled the dash completely out and found the culprit - a broken heater door (actuator with blue & red vacuum lines connects to it). My only issue now is how to get the broken portion out; does it just pull out?

Apparently, from surfing the internet, the part that is notoriously broken is: GM part #52470781 (heater control valve)

 

IIRC the heater case must be removed and split to get the door out. Might want to consider a new heater core as long as you're that far.

 

What is the process in that step, do you know? Will I have to rip half the engine out to do so?

 

There's a long discussion of this topic here. Heater assembly parts diagram is here. Picture of the door that breaks:

 

Thank you for the tips, I have picked up a heater core in addition to the heater door (valve).