YES THAT IS CORRECT, THERE ARE 4 TOTAL RELAYS, BUT THE ONE DESIGINATED A.C AND HEAT WHICH IS THE MAIN ONE IS THE ONE UNDER THE DASH, WHY THEY LABEL THEM THIS WAY IS ANY ONES GUESS, BECAUSE THE OTHER ONES CONTROL THE COMP, AND ONE OF THEM CONTROLS THE BLOWER MOTOR , GLAD YOU GOT IT LOCATED , BUT PLEASE GET YOURSELF A GOOD ISUZU ELECTRICAL MANUAL, IT WILL SAVE YOU A TON OF HEAD ACHS JERRY OH JUST SO HAPPENS I KNOW WHERE YOU CAN GET ONE FOR A GOOD PRICE..