A/C only blows out the defrost and floor vents?

2017 GMC SAVANA
95,000 MILES • 6.0L • V8 • 2WD • AUTOMATIC
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PAUL MALASKA
  • MEMBER
  • 1 POST
When I turn the A/C on it won't blow out of the dash vents but comes out of the defrost and floor. What would cause this? When it was working and coming out the dash vents it seemed to switch over to the defrost and floor vents when I would accelerate while on the freeway. The A/C in this van has been trouble since it was new!
May 24, 2023 at 2:46 PM
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STRAILER
  • CAR REPAIR CONTRIBUTOR
  • 54,189 POSTS
Yes, this happens when the mode actuator goes out or you have lost vacuum to the HVAC system which is a small vacuum tube under the hood. here is the location so you can change it out:

This guide can help as well:

https://www.2carpros.com/articles/air-vents-stay-in-the-defrost-position

Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.
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May 25, 2023 at 10:57 AM
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