What was found
ENGINE OVERHEAT LIGHT FAILS TO ILLUMINATE DURING TEST. ACFT GROUNDED. PERFORMED TASK 26-10-00-810-801 NO FAULTS NOTED, CYCLED A/C POWER, NR 1 ENG OVERHEAT LIGHT TESTED NORMAL. AFTER STARTING NR 1 ENGINE, THE OVERHEAT DETECT LIGHT ILLUMINATED. AFTER APPROX 5 SEC, THE OVERHEAT LIGHT EXTINGUISHED. AFTER TESTING AGAIN, THE NR 1 ENGINE OVERHEAT LIGHT FAILED TO ILLUMINATE. PERFORMED BITE ON ENGINE/APU FIRE DETECT FIM 26-10, TASK 801 NO FAULTS. VISUALLY INSP ALL TERMINAL ENDS ON A AND B LOOPS NR 1 ENGINE NO DEFECTS NOTED. RANG OUT WIRES IAW FIM 26-10-00-810-805, STEP F (3) (4) ALL WIRES RANG GOOD. RAN ENGINE AND PERFORMED OPS CK AMM 26-10-00 OPS NORMAL, UNABLE TO DUPLICATE DEFECT. REPLACED ENG AND APU FIRE CONTROL PANEL. FOUND ONE TERMINAL LUG ON RIGHT CORE A LOOP FRAYED. REPLACED A LOOP CORE FIRE DETECTION HARNESS. REF WDM 26-11-11, IPC 26-11-02-01, AMM 26-11-02.