95 trans am Stock H/U
 

Will a 95 head unit from a trans am work on a 02 model(firebird / TA) or so? Tried to hook it up the other day on a friends car and it didnt turn on

It should. Both models use the same connections and are ordinary head units in that they produce speaker-level output. Now a Camaro Bose head unit from the mid 90s is not the same and won't interchange without an adapter.