What was found
FLT 4463 AFTER TAKEOFF LEFT ENG TAIL PIPE HOT LIGHT ILLUMINATED PILOT RETURNED TO FIELD, LIGHT EXTINGUISHED ON LANDING, MAINTENANCE DISPATCHED TO INSPECT AC.AC SET ON GROUND DURING LIGHT RAIN AND PART APPEARED TO BE WET, CLEANED CANNON PLUGS AND FOUND MOISTURE, PERFORMED GROUND RUNS, OPS CHECK GOOD.