As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) LT ALTERNATOR FAILED LIGHT CAME ON IN FLIGHT. RETURN TO BASE. MECHANICS CHECKED CONNECTIONS ON ALTERNATOR AND FOUND ALL WIRING CORRECT. THEY REMOVED THE ALTERNATOR AND FOUND THAT THE FRONT BEARING ON THE ALTERNATOR HAD FAILED. THIS IN TURN HAD CAUSED THE CLUTCH ASSEMBLY TO FAIL WHICH HAD DAMAGED THE DRIVE GEAR ON THE CRANKSHAFT. ENGINE WAS REMOVED AND SENT OUT FOR REPAIR.