What was found
DURING CRUISE, ENG FIRE WARNING MASTER LIGHT AND BELL ACTIVATED MOMENTARILY. UNABLE TO DETERMINE WHICH ENGINE CAUSED PROBLEM. FUEL FLOW ON NR 3 ENGINE INCREASED APPROXIMATELY 700 PPH. SHUT DOWN NR 3 ENGINE, WITH ENGINE WINDMILLING, N1 WAS 26.5 PERCENT, N2 WAS 41.1 PERCENT AND OIL PRESSURE WAS 36 PSI. GROUND RAN NR 3 ENGINE. FUEL FLOW OPS CHECKED NORMAL. INSPECTED FIRE WARNING SYSTEMS ON ALL FOUR ENGINES. FOUND WIRE DISCONNECTED ON FIRE LOOP ON NR 1 ENGINE ABOVE DIFFUSER CASE. RECONNECTED WIRE, NO DISCREPANCIES NOTED ON NR 2 , 3 AND 4 ENGINES. FIRE WARNING SYSTEM OPS CHECKED GOOD.