Air blend door Actuator
I just had the "loud clicking noise behind the glove box" experience in my
2014 Impala. AC was only blowing through drivers side vents. I bought a
replacement air blend door actuator, easy to replace behind glove box, but
after starting the car the noise still occurs with outside air but goes away with
inside recirc air. I unplugged the actuator and started the car and the noise
still came on with outside air and went away with inside recirc air. Another
actuator somewhere?