No air out of eyeball level outlets

96 with 138K miles. Air blows out of defrost and foot outlets, but when I select the eyeball level nothing changes. In fact, if I select foot only, air still comes out of defroster also. I dread taking apart the dash which I think requires airbag and steering wheel removal. How can I narrow it down to switch or flapper stuck or motor inop or maybe relay? Also are the actuators vacuum driven or electric? Anyone have experience in this area?

the actuators are electric and chances are your head unit is malfunctioning.

Did an impedance check on the control head, the ohm readings were close, but replaced it with a used unit anyway for $45. Still no change in the malfunction. I've got the dash pretty much apart, so figure it has to be in the system that diverts the air. New territory for me....help.