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

PAUL MALASKA

MEMBER
2017 GMC SAVANA
6.0L
V8
2WD
AUTOMATIC
95,000 MILES

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!

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,637 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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