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Hvac Issue! Baffled!

4K views 8 replies 4 participants last post by  StevoElsupremo 
#1 · (Edited)
My girls Hvac is having an issue thats even baffling the mechanic. I'll try to explain this as best I can.

Ok so the heat to the upper (face) vents doesn't work, here's what I do know


1) it CAN'T be the heater core, Heat blows to the feet and windscreen.

2) heat WILL NOT blow to the "face" vents.

the mechanic doesn't know what the hell is up, we took the headunit out and could see the arm moving that directs air flow physically moving, so thats not broken..

The mech. had deduced that the face vents are tying to blow hot AND cold air at the same time(resulting in well..not hot air), so he programmed the car to only blow hot air all the time (its winter) this is temporary... but still, why the hell would it only blow room temp air out the face vents and not hot air?

It's a 2006 SS if that matters
 
#2 ·
Well your heater core has coolant that flows to it, ensure that your engine temp is reading on your DIC 189 degrees Fahrenheit. It flows from the engine block (hot) to the heater core allowing warm-hot air through the vents. You may also have a blend air door that is stuck and will not allow for heat to come through.
 
#3 ·
I thought it might be the blend door, but apparently its trying to blow hot and cold at the same time. He programmed the car to ONLY blow the hot air. I checked the heat temp as well and its getting up to proper temps. Remember, the hot air WORKS, it just wont blow to those vents..
 
#4 ·
Then it does sound like the blend air door. When its pointed up, it allows for air to travel from A/C unti to heater core fins, creating heat and exiting to the vents.
 
#7 ·
#8 ·
Once the door is mechanically engaging or electrically (haven't seen it in person, but they use either or), it flows to the vents through a bunch of tubes and comes out your vents. If the shaft is broken, you may be able to replace that, but in most OEM HVAC's, the unit is an all in one set.
 
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