As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ALTERNATOR CHARGE, FAILURE DUE TO LOOSE PULLEY FAN AND SHROUD ASSEMBLY. UNDER ANY LOAD SLIPPAGE OCCRUED . HEATED NUT AND LOOSENED ASSEMBLY. KEYWAY INSTALLATION WOULD SOLVE POSSIBLE PROBLEM AND PULLEY SLIPAGE. AIRCRAFT WAS REPORTING INTO IMC PREFLIGHT RUN UP, CHARGING FAILED.