If you have A/C in your Fiero, regardless of if it works or not.   The Fiero's that were equipped with A/C had Electric Servos to change the air location, Floor/Vent/Defrost, also a 2nd servo to change between recirculate cabin air or use Fresh Air from outside.

     Up until recently these have been a non issue, however I am hearing more and more often people asking about them, as it looks like this is the time that they start failing.   

         People are asking, where these servos are, and what it takes to replace them.

        Because to date I have never seen pics posted of the exact locations and most people don't have a clue as to where they are. 

These should give you a good reference point.

I have yet to call up a GM parts guy, to find out if these cross to any other GM car, I am sure they must.   As if they don't we are going to be really screwed.   If they are unique to the Fiero, the chance of finding them new will be slim to none.  

These are pics from my Heater Box from my 85GT.    Note the open area where you can see expanded foam is the heater core box.  The other side that looks like it would be heater core pipes is NOT the heater core area, that is the area for the main cabin wire harness pass-through.

      Well here are the pics.

The servos are the little black boxes with a wiring connector on them.  About the size of a 5$ bill folder in half.  

          To get access to replace them is going to be a major nightmare, as you can't even see them when the heater box is installed in the car.   You might be able to reach in and touch them, but un-hooking the clips, and bolts will be nearly impossible.

I do have some installed pics, and I'll have to find those and post them up later in this thread.