Heater air will not blow correctly

Tiny
WALTER WOOD
  • MEMBER
  • 1999 CHEVROLET LUMINA
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 300,000 MILES
I have changed the blower motor and switches the blower motor works fine, but for some reason even on high the air barely flows out of the vents, no matter where I put the blend doors (I have even unhooked and operated them manually just to check) it has no change. I have checked the duct work as best I can and have not found any clogs. I am totally stumped. Please help
Friday, December 7th, 2018 AT 9:58 AM

25 Replies

Tiny
ASEMASTER6371
  • MECHANIC
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Good afternoon.

When you replaced the blower motor, did you replace the cage as well? If you have a bad cage, the blower will work but not send air.

If that is good, then you have an issue in the ducts. Make sure all the ducts are together tightly and do not leak air. Air leaks are the common reason for this issue.

Beyond that, you will need to get inside the duct work and check the doors for operation.

Roy
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Friday, December 7th, 2018 AT 2:33 PM
Tiny
WALTER WOOD
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I did not know I could change the cage. It looks like it is all one molding under the dash, and getting to the duct work looks like I am going to have to pull the whole dash. That is my last resort in the winter.
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Friday, December 7th, 2018 AT 2:44 PM
Tiny
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Yes, that is correct.

Yes, the cage is serviced separate from the motor.

Did your replacement come with a new cage?

Roy
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Friday, December 7th, 2018 AT 2:46 PM
Tiny
WALTER WOOD
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No just the motor, looking at the diagram it looks like the vent motor is by the driver? It have two actuators turning different doors right next to the passenger feet, no matter where they are set the heat still just barely blows.
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Friday, December 7th, 2018 AT 2:48 PM
Tiny
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That is why these checks have to be done. You have to start somewhere and at the motor is where you start.

Roy
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Friday, December 7th, 2018 AT 2:50 PM
Tiny
WALTER WOOD
  • MEMBER
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Sounds good, I will start back at square one this weekend and let you know what I find. It has been a long day, yes the blower motor had a new squirrel cage on it.
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Friday, December 7th, 2018 AT 2:52 PM
Tiny
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Sounds like a plan.

We will be here to help.

Roy
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Friday, December 7th, 2018 AT 2:54 PM
Tiny
WALTER WOOD
  • MEMBER
  • 24 POSTS
Ok back at this lumina sir, I have checked fluid level n bled the coolant system, the new blower motor came with a new cage on it, still no matter what I do with the actuator doors it only blows thru the vent and very little when it does even with the blower on high, I cant see how to get inside the ductworking without taking the whole dash out of the car ( I really dont want to do this) im pullin my hair out on this
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Saturday, March 2nd, 2019 AT 4:53 PM
Tiny
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I understand.

You will need to look at the ductwork for any obstructions that will cause low air flow.

Since it is at all modes, it sounds like it is back at the blower motor.

I would start at the blower motor and remove it and look around and see if you see or feel anything that is causing the obstruction or leak.

Roy
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Saturday, March 2nd, 2019 AT 4:58 PM
Tiny
WALTER WOOD
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Ok is there a way to pull that part of the ducts out after I pull the motor?
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Saturday, March 2nd, 2019 AT 4:59 PM
Tiny
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Thats where you will need to back out the dash to access the ducts.

Roy
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Saturday, March 2nd, 2019 AT 5:04 PM
Tiny
WALTER WOOD
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Oh goodie lol I was afraid of that
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Saturday, March 2nd, 2019 AT 5:05 PM
Tiny
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Good luck.

Let me know how you make out

Roy
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Saturday, March 2nd, 2019 AT 5:07 PM
Tiny
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Will do thank you
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Saturday, March 2nd, 2019 AT 5:10 PM
Tiny
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Anytime.

Roy
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Saturday, March 2nd, 2019 AT 5:22 PM
Tiny
WALTER WOOD
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Okay, I was elbow deep in the box from where the blower mounts, all I can feel is open box and a couple messed up springs, I can't find what they go too no doors etc.
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Sunday, March 3rd, 2019 AT 10:33 AM
Tiny
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Okay, then you may have an issue right at the blower.

Was your blower motor new or used?

Roy
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Sunday, March 3rd, 2019 AT 10:36 AM
Tiny
WALTER WOOD
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New, I powered it up outside the box and it blows lots of air. Could it have not been sealed correctly? It had a little air leak around a small part of the seal but I couldn't tighten the screws anymore without stripping the plastic.
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Sunday, March 3rd, 2019 AT 10:38 AM
Tiny
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Yes. You can use some sealer such as RTV.

Listen for any other leaks in the duct work as well.

Roy
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Sunday, March 3rd, 2019 AT 10:48 AM
Tiny
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Will do.
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Sunday, March 3rd, 2019 AT 10:52 AM

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