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There is a vacuum supply liine that is under the hood towards the passenger side. It hooks into the manifold and has some small plastic lines are are common for cracking and breaking.
not sure if there is enough vacuum to activate change or if it operating properly. Saw a plunger move, but it didn't change
Not sure if I am getting enough vacuum, saw plunger change but air flow remained at feet
check the picture that I posted the line also has a check valve that could be bad as well. Normally when it is stuck in the floor vent only that is the default setting when vacuum is lost to the head unit.
The lever that you see moving may just be the temp blend door which is electric
sorry not electric, it's just a mechanical cable