As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
V-BELT FAILURE ON RT ENGINE CAUSED RT ALTERNATOR TO FAIL AND ENGINE COOLANT TEMP TO RISE. SHUTDOWN RT ENGINE AND FEATHERED THE PROPELLER. ACFT DIVERTED. V-BELT HAD RECENTLY BEEN REPLACED ON BOTH RT AND LT ENGINES. INVESTIGATION REVEALED POSSIBLE INCORRECT INSTALLATION OF V-BELTS ON BOTH ENGINES DURING MAINTENANCE.