• Welcome to SVTPerformance!

Issues with A/C blender door

Discussion in 'Fox Body Mustangs' started by turbov6joe, Sep 9, 2015.

  1. turbov6joe

    turbov6joe Defensor Fortis Established Member

    Nov 4, 2009
    Paola, Kansas
    When I'm running the A/C and accelerating, the air will not come out of the dash vents. Now, when I let off of the gas and the car goes into a high vacuum condition, the cold air momentarily comes out of the dash. Once the motor goes down on vacuum like when back on the gas, I can hear the air blowing around inside of the dash and feel some (minimal) come out on my feet. Can someone point me in a direction of maybe a vacuum T that might be going bad, or how about the actual vacuum hose that feeds the HVAC. This issue is repeatable and comes and goes with vacuum, or a lack thereof. TIA
  2. 2k7gtcs

    2k7gtcs Member Established Member

    Jul 26, 2010
    Just so happens I've got my AC box pulled for a heater core and I've had a similar problem to yours on my Bronco before. In the Broncos case it was the equivalent of the black vacuum line that runs from the engine compartment to the AC vacuum system inside. The Broncos line had become brittle in the heat and weather and was deteriorated. It was in pieces and couldn't hold an vacuum at all. So I patched it. And it solved the exact problem you have. AC blew fine at idle and under a little load but during acceleration and above about 50mph I got nothing.

    So I guess check this line out. You can see it comes out near the heater core coolant lines and the AC lines at the firewall.

    Maybe I'm wrong but its worth a shot.


    I'd check on that white vacuum line also.

Share This Page