I know historically a lot of vehicles used vacuum to control things. I have seen a lot of people mentioning vacuum lines to HVAC functions. I have a 4.7L 2002 Dakota and with the servo powered actuators I am wondering if there is still some aspect of the HVAC system that is dependent on vacuum.

 

Nope. In your 2002 all the actuators are now electric. Even the blend door is no longer cable controlled.