1998 JAGUAR XJ8L Electrical Systemwiringinteriorunder Dash Problems

1998 JAGUAR XJ8L CAR WOULD STALL WHILE DRIVING, WINDSHIELD WIPERS WOULD STOP AND START,HEAD LIGHTS WOULD GO OFF,INTERMITTENTLY. THIS MADE THE CAR UNSAFE TOP DRIVE. I BOUGHT THE CAR USED AND I DIDN'T KNOW ABOUT THE PROBLEM. WHEN THE PROBLEM STARTED I THOUGHT IT WAS A COMPUTER BOOT PROBLEM SO I TURNED THE CAR OFF AND THE PROBLEMS SEEMED TO DISAPPEAR. I FOUND THAT THE PROBLEM WOULD COME AND GO AND WAS SO INTERMITTENT IT COULD NOT BE PICKED UP WHILE AT THE CAR SHOP, DOWNTOWN JAGUAR IN MINNEAPOLIS, MN. I AM A CONTROLS ENGINEER AND THOUGHT THAT I WOULD TROUBLE SHOOT THE PROBLEM. I PURCHASED FROM THE INTERNET THE ELECTRICAL SCHEMATICS FOR THIS CAR. I FOUND THAT ALL OF THE SYSTEMS HAD A COMMON SOURCE. THIS SOURCE WAS A COMPUTER LOCATED UNDER THE DASH BEHIND THE GLOVE COMPARTMENTED WAS CALLED BODY PROCESSOR MODULE OR BPM. IT WAS SEALED AND...