Front HVAC controller same as rear?

[Red Rider]

So a while back, I replaced my rear controller for HVAC in my 2004 Tahoe. Here is thread on that.

http://www.tahoeyukonforum.com/forum/showthread.php?t=66001&highlight=blend+heat

I have noticed that when i get in my truck, turn on ignition, HVAC is off. I hear a constant whirring noise of motor. I believe this to be the blend door adjusting constantly. Am I right on this? If it is blend door, does it mean i have a bad controller? If not, what would it be.

Also, I believe I read that rear controller is the same as the front? New part 15832319.

Thanks.

 

[TTro33]

Did you reset the HVAC system to let it recalibrate?

 

[Red Rider]

Why would i recalibrate? I did when i installed new controller in rear. I did not do the front, yet.