Blower will only blow thru the befroster vent
The default defrost vent if the system has an actuator problem it will only duct to the windshield defrost vents. look around under the drivers side and passenger side operate the vent control knob listen and see if you notice clicking? try to isolate the problem. IF you can't use the FORD Factory IDS-VCM scan tool to tell exactly which actuator is guilty. Regards
Check for a disconnected vacuum line also
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