What was found
FL 280 LOWER AFT BODY OVERHEAT LIGHT CAME ON. BLEED 3 OPEN, RIGHT PACK OPEN. CARGO HEAT OUTFLOW NORMAL. FOLLOWED QRH PROCEDURE. DESCENDED TO FL 250, RIGHT NR 2 BLEED OPEN, RIGHT PACK ON. CARGO HEAT OUTFLOW NORMAL. INCREASED THRUST ON NR 3 ENGINE TO 85.5 N1. LIGHT STAYED OUT. REMOVED KEEL BEAM ACCESS PANEL IN RT WHEEL WELL. FOUND AFT BODY O/H DETECTOR LOOP IN KEEL BEAM AREA ALMOST TOUCHING PNEUMATIC SUPPLY DUCT. REROUTED LOOP AS REQUIRED. NO OTHER FAULTS FOUND. CLOSED ACCESS PANELS & RESTORED A/C TO NORMAL. PERFORMED TEST IAW MAINTENANCE MANUAL 26-14-00-5, NO FAULTS.