As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED BOTH ALTERNATORS FAILED. PILOT TRIED AUXILIARY REGULATOR, ALTERNATOR CAME ON-LINE FOR SHORT TIME, THEN FAILED. INVESTIGATION REVEALED THE FIELD OF THE RT GENERATOR WAS INTERMITTENTLY SHORTING TO GROUND. SUBMITTER SUSPECTED INSULATION BREAKDOWN DUE TO HEAT. SINCE ONE VOLTAGE REGULATOR CONTROLS BOTH ALTERNATORS, THIS FAILURE CAUSED THE LT ALTERNATOR TO FAIL.