A/C system

You have NO Vacuum or a vacuum control leak for control. I would first check vacuum lines in the engine compartment for they are known to break at the intake or the vacuum tank ( ball like thing ) If you are getting vacuum to the dashboard then its tear down time to find out why it is not transferring vacuum to the control levers for the vents. good luck

I have seen this on a few New Yorkers. Basically some plastic parts behind the dash can fatigue or crack over time. If your blower works on the windshield and floor but not through the dash vents then your problem is likely mechanical, not electrical. The odds are that a plastic piece broke that moves (when electronically told to) to shut off vents or open them. Unfortunately, you will have to remove the dashboard to access the broken part. It is a worthwhile fix as having air conditioning or heat when and where you want it is a key benefit of driving a high end luxury automobile such as the New Yorker. Good luck with your Chrysler!