UNDERHOOD FIRE OCCURED ON VEHICLE WHILE TRAVELING EB ON LIE. ENGINE COOLING FAN MOTOR SIEZED, RESULTING IN A UNINTERUPTED GROUND FAULT WHICH BURNED ALL THE WIRES IN THE MAIN WIRING HARNESS. THERE WAS NO CIRCUIT BREAKER OR FUSE PROVIDED IN THE WIRING TO PREVENT A GROUD FAULT FROM OCCURING. AUDI UPGRADED SUBSUQUENT MODEL YEARS OF THIS VEHICLE WITH A FUSEABLE LINK ON THE GROUND SIDE OF THE COOLING FAN MOTOR, BUT FAILED TO PROVIDE THE UPGRADE TO OWNERS OF 1984 THRU 1989 VEHICLES. COMPLETE DESTRUCTION OF THE VEHICLE WAS PREVENTED ONLY BY MY ABILITY TO DISCONNECT THE BATTERY CABLES IN A RAPID MANNER.