What was found
FLT 800 FROM KMIA TO MMUN. AFTER TAKE-OFF CLIMBING THROUGH 1,000 FT AGL, THE NR 3 ENGINE OIL TEMPERATURE BEGAN TO FLUCTUATE BETWEEN 100 DEGREES AND OFF SCALE HIGH. AT APPROXIMATELY 15,000 FT, THE NR 3 ENGINE STAYED OFF SCALE HIGH. REFERENCE AOM CHECKLIST FOLLOWED BY NR 3 ENGINE IN-FLIGHT SHUTDOWN AS PRECAUTIONARY, ADVISED ATC AND DECLARED EMERGENCY. AIRCRAFT AIR TURN BACK TO KMIA AND LANDED WITHOUT INCIDENT. AIRCRAFT WAS INSPECTED AND FOUND A BROKEN WIRE/PIN AT THE NR 3 ENGINE OIL TEMP BULB CONNECTOR. REPAIRED AND REPINNED BROKEN WIRE AT CONNECTOR, PERFORMED ENGINE RUN AND SYSTEM CHECK GOOD IAW MM 79-32-0 AND 20-11-1. AIRCRAFT RETURNED TO SERVICE.