The horn relay location on a 1982 Corvette isn't standardized in a single, easily-accessible spot like a fuse box. It's often integrated into other relay centers or tucked away within the car's electrical system. To find it, you'll need a wiring diagram specific to your 1982 Corvette. A Haynes or Chilton repair manual for that year and model will be your best resource. These manuals usually have detailed diagrams showing the relay locations and color-coding of the wires.
Without a wiring diagram, searching blindly is difficult and could cause damage. Using the wiring diagram will allow you to trace the horn circuit and locate the relay.