What was found
DURING CLIMB, ENGINE NR 1 OIL FILTER BYPASS LIGHT ILLUMINATED, REDUCING THRUST LEVER TO NEAR IDLE, LIGHT WENT DIM AND OUT THEN FLICKERED ON-OFF. ENGINE SHUT DOWN AND RETURNED TO BASE. ENGINE OIL CHANGED, PRESSURE FILTER REPLACED, ALL CHIP DETECTORS CHECKED SATISFACTORY, GROUND RUN PERFORMED. ALL PARAMETERS NORMAL EXCEPT FILTER BYPASS FLICKERS AT 90 PERCENT N2, CONFIRMED WIRING DEFECT.