I have A/C air blowing through the defrost vents and upper vents when set on max A/C or just upper vents are selected.
Jun 29, 2021 at 9:52 AM
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BMDOUBLE
CERTIFIED EXPERT
1,139 POSTS
You need to verify the vacuum source (black tube) under the dash has vacuum available. If there is no vacuum there, look under the passenger side of the hood and trace the vacuum line to make sure there are no brakes, pinched line, etc.