As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRFRAME GROUND PLUG IN HAS NEVER BEEN CONNECTED TO AIRFRAME GROUND. BASE OF RECEPTACLE WAS INSULATED FROM AIRFRAME GROUND BY PRIMER ON METAL ANGLE. WE FOUND COMPLETE ISOLATION FROM GROUND POINT TO FUEL FILLER OPENING, NO GROUND ON OUR FUELING OPERATIONS FOR PAST 3 YEARS. MFG SHOULD CHECK CONTINUITY ON AIRFRAME GROUND PORT AT MFG SINCE NO OTHER TIME IN LIFE OF ACFT IS IT REQUIRED TO CHECK.