HVAC blower issues

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Sep 30, 2012 | 10:39 PM

cutlass

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HVAC blower issues

My blower motor is having two problems at the moment:
1. It only works on the high setting only
2. When it does blow on high, there is a high pitched whistling coming through the defrost vents. It maybe somewhere else in the ducts, but I don't know where yet if it is. The whistling sound sounds like air rushing through a restricted space.

Any thoughts or ideas are appreciated.

Thanks,
Drake

Sep 30, 2012 | 10:47 PM

empiretc

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You should replace the blower motor resistor. that should correct the speed setting.

check the intake under the dash on the passenger side. there maybe something sucked up in there causing the noise.

Sep 30, 2012 | 10:56 PM

cutlass

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I don't hear the whistling in the floor vent mode, but I do in all other modes. Does that rule out an obstruction in the intake on passenger's side?

Sep 30, 2012 | 11:01 PM

empiretc

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Quote:

Originally Posted by cutlass

I don't hear the whistling in the floor vent mode, but I do in all other modes.

If you get the same noise on all other settings, then yes.

Something may have fallen into one of the vents. You'll have to put an ear to each one and check if you can hear something strange in one of them.

Sep 30, 2012 | 11:08 PM

cutlass

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I'll get in there and check the vents for an obstruction. However, I am a little dumbfounded at the blower motor resistor diagnosis. It does make perfect sense to me that the resistor would be the problem. It's just that the resistor is a brand new motorcraft part and has not seen one second of use yet.

I replaced it a while ago when I had my engine out because I noticed it was rusted out completely inside and out.

Does this make sense that a brand new resistor is not working?

Sep 30, 2012 | 11:18 PM

1fixitman

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From: Palatka, FL

I would take the resistor pack out and check all your connections are tight and free of moisture. Remove your motor and spin by hand. Feel for play in the bearings.

Sep 30, 2012 | 11:51 PM

cutlass

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Quote:

Originally Posted by 1fixitman

I would take the resistor pack out and check all your connections are tight and free of moisture. Remove your motor and spin by hand. Feel for play in the bearings.

I will do as you have suggested. I'm just wondering though...why would play in the fan motor bearings cause it to only operate in high speed setting?