Clicking noise coming from the glove box area. Heater fan speed doesn't affect noise. Actuators for temp and blend all work well. What else is under there ? Sounds allot like a leaf in the heater fan so I looked. All clear.

 

9 out of 10 it's your recirculation door actuator. Very common in these trucks. Change the controls to max ac I'd you have auto unit and if it's a manual unit turn recirculation on and off with blower running. You should hear a change in airflow whilst doing this. If you do not then your recirculation door actuator is bad.