Truck Repair: Heater control display, center vents, inspection mirror

Question
'92 Chev 1500. I think my son dropped a brass key into the defrost opening on top of the dash and I can hear something rattle when I bang the louver box under the dash. Electronic heater control display has all blend arrows flashing when defrost is selected.  Defrost is not actuated although the louver motor is functioning; I think spring loaded brackets connecting actuator motor to the upper door(defrost?)shows door not moving full travel cause I can see the spring mechanism in the motor to louver sliding brackets compress part way as motor moves linkage/ door. I have removed dash center vents and cannot reach problem area, nor can it be reached from floor opening. Two questions 1) What does the flashing display mean? 2) How might I extract the key if it is indeed the infracting article?  PS can you send your response to me directly to alleviate my concerns of returning to this site? feel free to post this on the message board

Answer
Hello Kevin,
That spring loaded lever would need to be compressing the spring a lot, and preventing the motor from reaching its full travel in order to cause the display to blink, if that would even cause it.

The complete housing can be removed from the firewall, but I would try a little harder through the center vents, with a mirror to do a good look inside. I seem to remember being able to reach something like an inspection mirror back in there.

That spring loaded controller actually controls a couple different doors I believe.

Van