1984 Celica GT-S

Does anybody know where I can find the diagnostic test connector on a 1984 Celica GT-S????

prolly a little black box somewhere under your hood by the firewall

mine is next and down from the battery ( driver side, the book says it is by your radiator resivoir ( passenger side) ( sp?). Mine has 3 female prongs on it. Are you talking about the check engine diagnostic?