Ok question. I have 96 blazer only blows out defrost and floor. the actuator that control the vents. I have good vacuum.They do not make them anymore and having a hard time finding any at junk yards is there any way to convert it to Electric actuators. Or is there another way to fix this?

 

How did you check your vacuum? The underhood vacuum hoses will rot and crack making the HVAC actuators not work.

Otherwise, I don't think I've heard of these failing. I'm surprised you have not been able to find replacements at a wrecking yard.

 

I replace all the vacuum lines. And the vacuum canister. I have good vacuum to the control. Then I took the dash apart and hooked each to all mityvac they don't hold pressure or move nothing. Only one that works is the one that controls the ac to heat

 

Yep, you did a great test.

So none of the vacuum controlled actuators responded when you applied vacuum to them using your Mityvac?

Could the problem be with the HVAC controls in the instrument panel?