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Check the floor vent, and defrost vent for airflow. If they have flow, you may have an issue with the control door linkage.
 

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Check your fan for an accumulation of leaves and debris.

The aftermarket fans are about 3/8" shorter installed height, that allows a tremendous amount of back flow between the top of the fan, and bottom of the duct, appreciably reducing the flow from the vents. You can easily tell the aftermarket ones from the OEM because the aftermarket squirrel cage is white.
 
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Discussion Starter · #7 ·
If it works on all four speeds... Probably a failing blower motor. Very very common. Easy to get to and to swap out.
Blower motor works on all 4 speeds.
Check the floor vent, and defrost vent for airflow. If they have flow, you may have an issue with the control door linkage.
Control door is closed
 

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Does it have the weak aftermarket Blower motor that is 1/2 the size of the oem? Do you hear any hissing under the dash? I had a stuck blend door the other day major vacuum hiss under the dash and rough engine from the vacuum leak
 

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Discussion Starter · #9 ·
Does it have the weak aftermarket Blower motor that is 1/2 the size of the oem? Do you hear any hissing under the dash? I had a stuck blend door the other day major vacuum hiss under the dash and rough engine from the vacuum leak
Thanks for the comment. I looked at the blower .motor and it doesn't look like its OEM. I do not have any vacume leaks . I wish I could feel what it felt like when the car was new and compare to now. Maybe that's as good as it gets.
 

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Thanks for the comment. I looked at the blower .motor and it doesn't look like its OEM. I do not have any vacume leaks . I wish I could feel what it felt like when the car was new and compare to now. Maybe that's as good as it gets.
To get the original feel, you need to recharge the system with R12 replacement, and put an OEM blower in place of the aftermarket one. The replacement R12 is about $44/lb. The fans can still be found in junkyards. An option to changing the fan is to put a foam gasket on the bottom of the inlet so that it is close to the top of the fan squirrel cage. 1/4" would help a lot, because the distance is almost 3/8". Just be sure it does not hit the top of the fan.

The aftermarket fan has a white squirrel cage, and the OEM is black.
 

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Try a ring of 1/4 inch hard foam glued to the bottom of the inlet at the top of the fan.
 
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