You are correct, the AC generally runs whenever the climate control is in the "Auto" position....it "conditions" the air - not just cools it. Basically, it greatly reduces the humidity in the air (more comfort and keeps the window from fogging) and will run even if the temp is cold and only heat is needed. This is the way it works in all my vehicles.

 

Not sure of the exact cause but I found a fix. I just placed a small plastic shim between the plastic door panel and the metal door frame. Seems like there is actually something that is loose inside the door panel (wiring?)and by shimming it a little makes whatever is loose in there not bump up against it anymore.

Kinda sucks having to do this cheesy stuff to a new truck but it worked and I don't want to remove the whole door panel to find out exact what is going on cuz I'll probably mess something else up.

 

I don't know what the fuss is all about. The auto climate control system is just that - automatic. Dial the temperature you would like and leave it to the system to think of how to heat or cool the cabin air to meet your desire. If it runs the A/C system, so be it.