squeak from the A/C vents. 2017 Ram 1500 5.7

Pull the fan and apply lube??

I presume you're referring to the HVAC Blower

I doubt you've got enough hours on it to wear the bushings out - but there is a chance that there is a out of round blower wheel or debris in the scroll rubbing on the blower wheel. It should be serviceable from beneath where it is covered by a trim panel. Minimal tools and simple electrics to disconnect and re-connect.