hey there, i have a 1986 fiero gt and i have to replace the belt which is beside the battery compartment. i just bought this fiero and i have asked a few mechanics around where i live and they keep on sayin there should be a belt tensioner. only one old mechanic told me that the alternator is in a bracket that i have to loosen up a bolt at the bottom and it will slide freely. however i have a problem since there looks to be no way to get my hands or tools in to get to this bolt. do i have to remove the rear panels? or any engine parts or is there something i'm just not doin?

old guy is right.

loosen the top bolt on the alt,
then loosen the bottom bolt.
now the alt will swing in towards the engine at the bottom.
remove belt,
install new belt.
swing alt away from engine.
use a prybar to keep the belt tight while you tighten the lower bolt.
tighten the upper bolt.
start car and listen to the squeel.
and repeat.

i do everything from the top.

You should be able to get to everything from the top, but it can be a pain. Sometimes it's easier to reach the lower alternator bolt from underneath the car.

But the old guy is right, Fieros don't have a spring-loaded tensioner from the factory, however if you want to use one look here: https://www.fiero.nl/forum/Forum2/HTML/074076.html

Having just upgraded to the CS alternator yesterday, it was easier for me to get the bottom adjustment bolt from the wheel well with the right rear wheel removed (car on jackstands, of course). The bottom bolt is right there behind the flex material.