Noises comming from my EATC (Behind it)

[kidrock52]

When I use my EATC (Heat, Vent or AC) There is a thumping sound comming from behind the EATC in the dash. When the fan is on low it is quiet. When it is on high it is quite loud. I have also noticed that it only puts out heat. When the AC is on it is hot. When cool air is on through the vents it is hot. Does anyone know what this is and how to fix it??? Thanks, Ed

 

[Slo-Sho]

Blend door module. The dash has to come out.

 

[93SHO'nOFF]

The blend door accuator is bad.The gears inside of it are plastic and wear out,causing a popping noise (teeth are stripped out on gear inside accuator)at all times because the accuator tries to move the blend door and can't .The inside temp sensor never sees the change in temp and keeps trying to move the door to make it hotter or colder.
Later

 

[ShadetreeSHOguy]

yep, blend door motor, first thing i fixed on mine when i got it back in august, dash has to come completely off, and if ya got the money, id go ahead and change the heater core to save from further headache, good luck

 

[kidrock52]

Thanks

I thank you all for the input. At least it will give me a chance to paint the dash too.