Toyota Repair: a/c flow seems blocked, filter is clean., control doors, control cables

Question
While driving with a/c on, vent output just dropped.  It still blows well on the feet, but all other vents seem clogged.  I pulled the cabin filter, but that is not the problem.  The compressor is still working, and the fan changes speeds, but 4 used to feel like a windtunnel, and now it's just a trickle.  Where is the intake?  Could it be blocked?

Answer
Without knowing what year/model it is I can't be of too much help but it sounds like a control cable has become disconnected from the air control doors in the air ducting, move the control lever or knob that controls where the air is output and check under the glove compartment and the left side under the dash at the heater controls to see if any of the control cables are disconnected from the operating levers.