As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, THE LT ENGINE ALTERNATOR STOPPED PRODUCING POWER DUE TO THE DRIVE CLUTCH SLIPPING. AFTER LANDING, REMOVED ALTERNATOR AND CHECKED THE DRIVE CLUTCH. COULD TURN THE CLUTCH BY HAND WITH SOME FORCE. REPLACED THE CLUTCH, REGULATOR AND ALTERNATOR. PERFORMED AND GROUND RUN AND THE CHARGING SYSTEM WORKED AS DESIGNED. REGULATOR REPLACED DUE TO THE RT ENGINE ALTERNATOR HAVING AND INTERNAL SHORT WHICH CAUSED A POWER SPIKE TO TRANSMIT THRU THE WIRING TO THE REGULATOR. NO OPERATIONAL PROBLEMS NOTED BEFORE FAILURE.