As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A REVERSE CURRENT RELAY REPLACEMENT IT WAS NOTICED THAT AT SOME TIME A GROUND WIRE AND POWER WIRE HAD RUBBED TOGETHER AND THE BURNED OFF THE INSULATION ON THE WIRES. THIS WAS NOT NOTICED BY ANY PILOT, NO BURNING ODOR WAS REPORTED. THIS WAS FOUND TROUBLE SHOOTING AN UNRELATED GENERATOR SNAG.