HVAC fan stopped working, on any speed, at any temperature setting. Diagnosis?

There are several possible causes of the symptom you describe. The most likely is that the blower controller, aka blower resister has failed. Late model Chrysler products are known for a pattern failure of the blower controller melting due to high current flow. If this happens, replace the controller and the blower motor. The blower motor is drawing too much current which melts the controller.