Not all 80 series corolla had ac, the hvac box was literally an HV box with provision to install an evaporator for the AC. Making it an HVAC box.
Same for wiring, it had plugs for the ac button, ac amp and even the 2 speed twin cooling fans infront of the car, all you needed was to remove the old wiring and plug in the new wiring at the fuse box, install an idle up vsv (wiring already provided) while for interior you only needed to add 2 pieces of wiring.