What was found
NR 1 FIRE INDICATION WITH BELL AT MAX POWER DURING TAKE OFF. INITIATED REJECTION AT 120KIAS. SHUTDOWN ENGINE AND FIRED AGENT BOTTLE. FIRE INDICATION QUIT AFTER THROTTLES RETARDED TO IDLE. R & R A & B UPPER TURB LOOPS AND RAIL ASSY IAW MM. REF 26-11-03-4, IAW FDCU1 ADJ/TEST IAW MM REF 26-11-02-5 AND CLEARED A LOOP FAULT. FDCU1 STILL SHOWS 'UP RT FIRE DET ASSY B'. T/S IAW FIM 26-11 AND VERIFIED RESISTANCE, FIG 103, SH2 AT 1450 OHMS BETWEEN PINS J & K, ALSO CONTINUITY BTWEEN J & K TO GROUND. CONTINUED SHAKE AND FOUND A PREVIOUSLY REPAIRED WIRE HARNESS SHOWING ERRATIC 'B' LOOP CONTINUITY. READING DURING SHAKE. PERFORMED RTS ON FDCU1 ALL TESTS GOOD ON LOOP A.