Blower wheel issues

[phatz_hatz]

Have a 95 4 door TBI, just replaced every single ac component with the exception of the evap coil. I get good cold Ac but i just feel like it does not blow it as forceful as it should. Temp drop is about 20-30 degrees. I am an hvac technician so i have it dialed in to proper subcooling. I just don’t wanna open up the blower if it’s just typical for these to blow “weak” all fan settings work. Tyia

 

[Eman85]

Pulling the blower motor is simple. Good chance you have leaves, mouse nest or something else in the housing blocking air flow, pull the motor.

 

[east302]

If the face of the evaporator is clean as mentioned above, then it’s probably as good as it gets. The next generation truck had much better airflow than these. I usually just keep the passenger vents closed on mine to get a bit more cfm on my side.

 

[LsHart]

There are foam gaskets thru out the hvac and turn to dust. Air will blow or leak out at those points. Does the fan work on all speeds?

 

[OR VietVet]

"Blow weak on all fan settings"? same output no matter the speed or the speed and force air does increase but still seems weak for the increased speed?

 

[phatz_hatz]

"Blow weak on all fan settings"? same output no matter the speed or the speed and force air does increase but still seems weak for the increased speed?

All fan settings work, they’re just all weak being the fastest speed comes out just not as forceful as let’s say my work van. If you read OP it says “all fan settings work”

 

[OR VietVet]

All fan settings work, they’re just all weak being the fastest speed comes out just not as forceful as let’s say my work van. If you read OP it says “all fan settings work”

Yes, I saw that. I am just asking if the fan speed picks up as it should but the velocity of the air stays the same, like it blows the same velocity on high as it does on low. If the velocity does increase but still seems to be way less than it should, then it has likely a blockage or seal leakage as has been stated.

 

[phatz_hatz]

"Blow weak on all fan settings"? same output no matter the speed or the speed and force air does increase but still seems weak for the increased speed?

Increases speed of fan but is weak

 

[LsHart]

If it does speed up as fan speed is demanded then. The squirrel cage is slipping on the motor or bleed outs at joints.

 

[LsHart]

Pull the right upper vent on the dash above the cup holder and u will see the foam or insulation

 

[east302]

There are foam gaskets thru out the hvac and turn to dust. Air will blow or leak out at those points. Does the fan work on all speeds?

You bring up a good point about air leaks.

phatz_hatz, if the dash vents are selected does air leak out from the center floor vent? The dampers have a rubber perimeter seal that eventually rots away and causes air to leak out. That definitely decreases air flow from the dash vents.

The picture below is one of them - the new GM part is on the left and the original on the right.

 

[YukonGTmaster]

I would check that your blend door actuators are serviceable as well. I have had them fail, and not direct the cool air out of the dash vents. I have also had water pooling in the blower motor duct, causing a multitude of issues.

 

[phatz_hatz]

I would check that your blend door actuators are serviceable as well. I have had them fail, and not direct the cool air out of the dash vents. I have also had water pooling in the blower motor duct, causing a multitude of issues.

This i figured out already originally it would only blow feet and defrost and extremely faint to face, one of the doors fell off the actuator and now it cycles through feet, defrost and face vents

 

[phatz_hatz]

I would check that your blend door actuators are serviceable as well. I have had them fail, and not direct the cool air out of the dash vents. I have also had water pooling in the blower motor duct, causing a multitude of issues.

This i figured out already originally it would only blow feet and defrost and extremely faint to face, one of the doors fell off the actuator and now it cycles through feet, defrost and face

You bring up a good point about air leaks.

phatz_hatz, if the dash vents are selected does air leak out from the center floor vent? The dampers have a rubber perimeter seal that eventually rots away and causes air to leak out. That definitely decreases air flow from the dash vents.

The picture below is one of them - the new GM part is on the left and the original on the right.

View attachment 485823

this is I’m not to sure about I’d have to check if i recall from last time i was in it i think it’s fairly faint but does come out the middle with dash vents only on

 

[LsHart]

U can go to Autozone and on the RTV isle, get a roll of like 3/4 to 1 inch single sided foam to replace what is easy to get to. That alone makes a difference. And if the vacuum manifold is worn change that to. So head unit.

 

[LsHart]

Check the vacuum lines running into the fire wall. If I remember, there on the passenger side tip area?