1997 Mazda MX-5 Miata

I HAVE A 1997 MAZDA MIATA WITH 113,000 MILES. IT HAS BEEN A GREAT CAR UP UNTIL THIS RECENT PROBLEM. IT STARTED OUT THAT THE "METER" FUSE WAS FAILING INTERMITTENTLY. WHEN THE 15 AMP FUSE WAS REPLACED IT WOULD WORK FINE FOR APROXIMATELY 2-3 MINUTES (MAYBE LESS) AT WHICH POINT I NOTICED THE "SERVICE ENGINE" LIGHT IS NOW ON AND THEN THE FUSE WILL FAIL AGAIN. THIS HAPPENED SEVERAL TIMES UNTIL NOW. NOW WHEN THE FUSE IS REPLACED AS SOON AS THE IGNITION CYLINDER IS CYCLED THE FUSE FAILS INSTANTLY. I AM AN AUTOMOTIVE TECHNICIAN, AND CHECKED A WIRING SCHEMATIC AS TO WHAT THIS "BLACK-YELLOW" WIRE ON THE "METER" FUSE SUPPLIES. BY THE WAY, AT THIS TIME I HAVE NO TURN SIGNALS, TACHOMETER, GAUGES OR WARNING LIGHTS. THIS PROBLEM IT DRIVING ME INSANE!!! I WENT THROUGH THE MANUAL AND DISCONNECTED EACH COMPONENT INDIVIDUALLY TO TEST THE CIRCUIT AT WHICH EACH TIME THE FUSE STILL FAILED. THE LIST OF COMPONENTS I TRIED ARE THE OXYGEN SENSORS, THE ECM, THE TURN SIGNAL SWITCH, AND THE INSTRUMENT CLUSTER (CRUISE CONTROL IS ALSO ON THIS CIRCUIT, BUT THE VEHICLE IS NOT SO EQUIPED) ALL TO NO AVAIL!!!! AM I MISSING SOMETHING? IS THERE A SHORT IN THE WIRING HARNESS ITSELF, IF SO, ANY SUGGESTIONS AS TO WHERE I SHOULD EXTEND MY SEARCH? THIS HAS BEEN A PROBLEM FOR ABOUT 2 WEEKS NOW AND I AM UNCOMFORTABLE DRIVING THE VEHICLE WITH THE ABOVE STATED CONCERNS. ANY INFORMATION YOU CAN GIVE ME REGUARDING THIS CONCERN WOULD BE GREATLY APPRECIATED!!!.*AK