what auses the a/c make a loud humming sound only on high speed

2002 PONTIAC FIREBIRD
77,000 MILES
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BILLMILL5050
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a/c set at coldest has 4 speeds no noise but just on 4th speed
May 20, 2012 at 12:27 AM
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SATURNTECH9
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If the loud humming noise is coming from the blower fan motor then sounds like you have a bad bearing in the motor etc.
May 20, 2012 at 12:44 AM
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BILLMILL5050
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it only does it on high not on low or med
May 20, 2012 at 7:07 AM
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SATURNTECH9
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Have you dropped the motor and checked the squriel cage for leaves debris etc?
May 20, 2012 at 7:10 AM
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BILLMILL5050
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no where is it under dash
May 20, 2012 at 9:15 PM
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SATURNTECH9
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There you go.
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May 20, 2012 at 10:14 PM
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BILLMILL5050
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i took off the glove box to get to the motor but i dont know what it is but its in front of the heater core when i masshed it the humming sound quits any idea what it is i posted pic what it looks like
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Jul 13, 2012 at 8:18 PM
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BILLMILL5050
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another pic
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Jul 13, 2012 at 8:24 PM
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SATURNTECH9
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Thats a bad pic can you take a actual pic of it and post it or email it to me?
Jul 13, 2012 at 8:28 PM
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BILLMILL5050
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ok ill post if not where do iu e-mail u?
Jul 13, 2012 at 8:58 PM
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BILLMILL5050
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3 more
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Jul 13, 2012 at 10:25 PM
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BILLMILL5050
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1 more
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Jul 13, 2012 at 10:30 PM
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BILLMILL5050
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where did you get your diagrams at?
Jul 13, 2012 at 10:33 PM
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BILLMILL5050
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i ran ac it open & closes a door when u go from ac to max ac
Jul 14, 2012 at 12:13 AM
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SATURNTECH9
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Thats your recirculation door actuator.
Jul 14, 2012 at 12:25 AM
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