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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: Stewart G Griffin on October 03, 2010, 09:27:42 pm
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i have a really bad whistling noise only when moving. If i turn the fan on full sometimes it goes away completely. Sometimes it will get softer.
Any suggestions?
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Air seal somewhere. Does it go away if you crack a window open slightly? My wing window on my 85 started yesterday for the first time...
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It seems to get a little quieter if i crack the window. But only a little quieter.
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Where is it coming from? Window, door, floor, AC, Vents?
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Not sure---seems more to the passenger side. It's LOUD.
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Whistling or squealing? Unplug the blower motor and see if it stops.
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alternator bearings? water pump bearings? blower fan bearings (already mentioned)? Or, all the women on the sidwalk actually whistling at you as you go by?
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It basically went away, but i'm thinking it's something under the dash so i'll be checking that. i don't think it's the blower because if anything it starts to go away if i turn ON the fan.
i know it's not the alternator or water pump.
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i don't think it's the blower because if anything it starts to go away if i turn ON the fan.
If it goes away when you turn it on it's most likely the blower motor. - Very common for them to squeal
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So it moves even when it's turned off?
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you can't turn the blower off---at least not on my trucks. Lowest setting, the blower still runs very low---something about keeping a positive air pressure in the cab or air circulating or something I've heard like that.
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It always runs to keep the plenum dry.
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i.c.---will check the blower fan.
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It always runs to keep the plenum dry.
Do you mean the cowl?
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No, I mean it prevents condensation in the box where the fan blows at the heater core, and the related ductwork. Not exactly sure what it's called, but it's a plenum of sorts.
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Whistling or squealing?
No Vile, I'm sure Stewart doesn't have livestock in the cab!
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I had leafs in my fan when we replaced the motor mad some weird noise so I stuck my hand in it lol scared me to death once I touched the fan forgot all about it being on
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You are correct Irish. It is called an air distribution plenum by many manufacturers.
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Cancel it: i didn't have the passenger door closed all the way. :P You know how it latches without being completely shut? That's what happened.
i am, however, having problems with the defroster not really working----air isn't coming out of the top of the dash. Also, the fan doesn't seem real powerful when put on highest notch.
i will try the search function as well.
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I would look for leaves in your blower motor or air ducts. Also if you turn off some vents, it can cause the others to whistle. At least that's what happens on my Honda. Most of the HVAC on my truck doesn't work, so I'm just guessing there.
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Sorry. I should have refreshed the page before answering. It was hours old when I posted.