What was found
LANDED UNDER AMBER ALERT DUE TO NR 2 ENGINE OIL FILTER BYPASS LIGHT. DETECTED A BROKEN SHIELD WIRE AT OIL FILTER SWITCH CONNECTOR. RETURNED TO ORD DUE TO NR 2 ENGINE OVERHEATED AND SHUTDOWN. SUPPLEMENTAL DATA UPDATE CREW REPORTED NR 2 ENGINE OVERHEAT INDICATION AT CLIMB. CREW SHUT DOWN NR 2 ENGINE PER QRC. PERFORMED TROUBLESHOOTING OF THE OVERHEAT DETECTION SYSTEM. FOUND NR 2 ENGINE CORE DETECTOR M1122, LOOPS A & B WITH LOW RESISTANCE SHORT TO GROUND. REMOVED AND REPLACED OVERHEAT DETECTOR CORE LOOPS A & B. ENGINE OVERHEAT DETECTION SYSTEM TESTED NORMAL. REPAIRED SHIELD WIRE. REPLACED OIL FILTER AND DIFFERENTIAL PRESSURE SWITCH.