1990 K5 Heat/AC Selector not working

[RunwayHead76]

After a motor upgrade, I got my AC working again…sort of. It was not a week later that my lever to select my floor vent defrost or AC positions stopped working. No matter what I set it too, it just blows on the floor and just barely through the vents. Looked at LMC truck for parts to fix it and came across a “rotary select switch”. Not sure if that is what I need to fix it. I have looked on YouTube and can’t find anything specifically about it. I will happily take any thoughts on it from the square body experts on here. Thanks in advance for the help.

 

[cheavyk10]

It's vacuum operated you might have a disconnected or cracked line.

 

[RunwayHead76]

I’ll start there. Maybe a line has gotten pulled loose. Thanks for the help.

 

[frankin5]

There is also a plastic clip on the blend door that breaks.

 

[Wes Harden]

Looks like this that one is broken

 

[The_Tomato]

I’ll start there. Maybe a line has gotten pulled loose. Thanks for the help.

any resolution? I'm having a similar issue where mine just won't go all the way to defrost.

 

[RunwayHead76]

Not yet. I am finally getting to get to it this weekend. I will definitely let you know

 

[RunwayHead76]

any resolution? I'm having a similar issue where mine just won't go all the way to defrost.

Finally got to get my head under the hood to look for disconnected vacuum lines. No luck. Everything looks like its hooked up. Of course I have a spaghetti plate of black wires and hoses. I’m going to check the lines for cracks in the engine bay before I check in the dash. I dread having to do that.