2008 3500 - Weird clicking sound after switching heater setting

I was defrosting the ole girl this am, and when I went out and switched the airflow from defrost to passengers, I started getting a weird clicking sound. I tried:

- Switching settings back to defrost
- Changing heat settings
- Shut down the truck - clicking continued!!!
- Bigger Hammer techniques - banging, thumping and general cursing...

Had no heat to speak off - So I am thinking the air flow door to the heater core...

Said screw it and did my running around. No change - clicked continually - stopped and shut down or running.

Got home - thinking I would have to rip my dash out... once again... to see wtf was wrong.

Pulled into the garage - and to avoid running down the battery and other potential issue, disconnected the batteries. Brain storm... Hook em up and see what happens....

No #@)(#$*$&* Clicking... I by no means think the issue is gone, but now I have some other things to consider like relays...

Throwing myself into the arms of the TDR community here to see if anyone might have an idea of what the bleep is going on, before I rip apart the dash and find out it was something else, and trivial!!!

Oh and no codes were showing...

Hoping everyone is safe and ready for the holidays!!! Thanks all

 

It will be a failing hvac actuator..Listen carefully to see what area it’s coming from,some are accessible with very little disassembly of dash components

 

I just rebuilt the whole assembly this summer, basically because the damn plastic tabs on the doors had broken. Replace the doors, heater core, and AC components. I thought it might be one on the door actuators, but it occurred even when the key was off. There was no heat to speak off, so I was guessing that door was the issue. However, after reconnecting the batteries the next day... nada... Then I fired it up and warmed it up.. heat as well... I'm not betting it's gone away, but I can try and pinpoint it at this time! Thanks for the reply Bob4x4!!!!