Front blower only operates in defroster mode

2003 HONDA ODYSSEY
165,000 MILES • 3.7L • 6 CYL • FWD • AUTOMATIC
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WARMIL27
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  • 1 POST
Today, the front blower will only operate in the defrost mode. Temp control and fan speed work and control unit show displays when pressed by will not divert air to other vents. Any ideas?
Feb 18, 2015 at 6:26 PM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
The air flow vents, which direct air flow direction, are actuated by engine vacuum. My guess is there is a vacuum leak that is causing the system to stay in the default mode of defrost. What you need to do is check under the dash for damaged or disconnected vacuum hoses as well as checking the vacuum supply from the engine.

When checking, start the engine and listen for a hissing sound which could help you locate where the leak is located.
Feb 18, 2015 at 7:57 PM
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