What was found
NR 1 ENGINE OVERHEAT LIGHT AND ENGINE NR 1 FIRE HANDLE LIGHT DOES NOT ILLUMINATE. DURING OVERHEAT/FIRE TEST WITH OVHT DET SWITCH IN NORMAL POSITION. ACFT GROUNDED. CONFIRMED FAULT. ENGINE NR 1 FIRE DETECTION TEST OK IN A OR B SELECTED, BUT FIRE HANDLE LIGHT DOES NOT ILLUMINATE WHEN IN BOTH/NORMAL POSITION. M279 (E/E) ENGINE/APU FIRE/OVHT DET CONTROL MODULE SHOWS WIRING OPEN/DETECTORS FAULT. FOUND NR 1 ENGINE UPPER FAN COWL AFT C-CLIP LANYARD RESTING ON THE UPPER FAN B-LOOP SENSOR. RESECURED LANYARD, NR 1 ENGINE FIRE DETECTION SYS OPS CK NORMAL REF AMM TASK 26-11-00-710-801.