Recently changed the heater core on my '91 Camaro RS and now I have NO air coming out of any of my vents, not even the defroster vents. Replaced the fan a couple of years ago and it is blowing great.

Where do I start?

Thanks in advance.

 

If your fan is definitely working then it has to blow out somewhere. I think the default is out the defroster vents even if all the doors don't work, isn't it? I'd check to see if it works with the AC, and if not then I'd check the plenum to make sure it is intact from the heater box to the vents. Other than that I can't figure why you wouldn't get air somewhere. Last resort is checking the fan wheel to make sure it isn't free-wheeling on the fan motor - but that would be a bizarre problem.

 

Check the wires that connect to the blower motor, Mine have come loose before.

 

Fan is blowing great. Air comes out by the heater core if i leave the plastic cover off under the dash but doesn't come out any of the vents if I put the plastic cover back on.

 

Maybe I wasn't clear enough when I originally posted the message. Fan is working great in the car, replaced it a couple of years ago. Air was blowing out of all my vents but I wasn't getting any heat. Replaced my heater core and now have heat blowing past the heater core into the passenger floorboard if I leave the covers off under the dash. If I replace the covers under the passenger side dash, I don't get any air out of any of the vents, not even the defrosters.

 

you probably put the litte selection valve in the heater box in incorrectly.

 

Is this what selects between heat or air? That seems to be working.

 

scratch that then