As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON PREDEPARTURE CHECK, NR 1 ENGINE DETECTOR GROUND FAULT LIGHT ILLUMINATED ON CIRCUIT BREAKER PANEL P6-3. CLEANED CONNECTORS AT THE RESPONDER AND THE TAIL CONNECTOR WITH NO JOY. RESECURED ALL CLIPS ON THE DETECTOR ELEMENTS AND GROUND FAULT LIGHT WENT OUT. SYSTEM TESTED GOOD PER MM 26-11-00 P501 & 502.