Vents stuck in defrost

1999 FORD F-350
253,000 MILES • 7.3L • V8 • TURBO • 4WD • AUTOMATIC
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GARRETT CRAWFORD
  • MEMBER
  • 1 POST
Bought a truck with vents stuck in defrost. I can turn dial to any position, even max AC and still stuck on defrost. With that case how do I fix the issue? Also, does the AC turn on when vents are in the AC position? I have turned dial to AC and max AC to see if I can get cold air out of defrost vents. Does not seem to kick on AC.
Jul 18, 2017 at 11:41 PM
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STRAILER
  • ✓ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
Hello,

Please Check the vacuum lines headed into the firewall which run the defroster and heater. Here is a guide that should help you get the problem fixed.

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

Please let us know what you find.

Cheers, Ken
Jul 19, 2017 at 1:14 PM
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