What was found
AFTER DEPARATING PHTD EN ROUTE TO PHNL - FLT 7723 - JUST AFTER LEVEL OFF, LOWER AFT BODY OVERHEAT LIGHT ILLUMINATED. LIGHT GOES OUT AFTER ONE MINUTE, WHEN NR 3 THRUST LEVER IS RETARDED. LIGHT ALSO GOES OUT IF NR 3 BLEED IS CLOSED AND NR 2 BLEED IS OPEN. THRUST LEVERS NORMAL. MADE UNEVENTFUL FLIGHT AND LANDING AT PHNL. IN PHNL, RAN NR 3 ENGINE AND OPENED BLEED VALVE AT PART POWER. COULD NOT DUPLICATE DISCREPANCY. SYSTEM OPERATES NORMALLY. NO OTHER DISCREPANCIES NOTED. AIRCRAFT RETURNED TO SERVICE. (X)