Noise from A/C - Bad Blend Door/ Vent Door/ Recirculation Actuator ?

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by bhsballer76, Aug 25, 2013.

  1. bhsballer76

    bhsballer76 Member

    I am having this really annoying noise coming from what seems to be the passenger side defrost vents on the top of the dash near the windshield. The best way I can describe the noise is as " screeching" sound. There does not seem to be any method to the madness. As long as I am driving, the noise will start and stop, then start and stop. It seems to last for anywhere from 5-25 seconds and will stop for the same period of time before starting again.

    The truck is a 2004 Silverado 1500 LS with dual climate control. It started after I had to carpool with someone to a meeting, and left my truck in a parking lot backing under the Florida sun from around 8:00 a.m to around 4:00 p.m. This is the first time EVER i have heard any noise from the A/C

    I have done a little research and there seems to be some decent information on bad Blend door, Vent door, and Recirculation door actuators. My confusion is that the noise coming from my truck is nothing like the "Clicking" sound described by most others. Also, as I stated before, the sound doesn't seem to be triggered by any certain position of temperature, vents( direct, floor, defrost), or driver or passenger selection. I put both sides individually on heat and it began to blow heat as it should.

    Does my truck have all three ( blend door, vent door, recirculation door) actuators?

    Any other thoughts on what the problem might be? Please help!!!
  2. 89steveo50

    89steveo50 Rockstar

    Does the screeching noise increase as the fan speed increases? and does it make sound when you have it on any other setting, via face or floor.?
  3. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    I would drop the blower fan and see if there are leaves in it.
  4. bhsballer76

    bhsballer76 Member

    The screeching sound doesn't increase with fan speed, it just becomes harder to hear due to the noise of the fan. The sound seems to occur with any setting.

    The sound has NOT occurred for the past 2 days. Not sure what caused it or if it will come back.

    - - - Updated - - -

    Any idea where this is located?
  5. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    Yep. on the passenger side under the dash you will see a large black plastic cover. There a a few small bolts in that cover. You pull the cover off and should see the blower motor. It should take you less than 10 minutes to get apart and put it back together. While you have the cover off you might want to change your cabin air filter if your truck has one.

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