What was found
PILOT STATED THAT THE LT PROP DID NOT FEATHER AFTER ENGINE SHUTDOWN IN FLIGHT, 2 ATTEMPTS, ENGINE CONTINUED TO WINDMILL. VERIFIED FAULT ON GROUND, ENGINE SHUTS DOWN BUT PROP DOES NOT FEATHER, INSPECTED PROP CONTROL PANEL FROM REAR NACELLE FOR BROKE WIRES AND RESISTANCE VALUES, NO DEFECTS NOTED. VERIFIED FAULT ON GROUND, ENGINE SHUTS DOWN BUT PROP DOES NOT FEATHER. INSPECTED PROP CONTROL PANEL FROM REAR NACELLE FOR BROKEN WIRES AND RESISTANCE VALUES, NO DEFECTS NOTED. R & R LT ENG PROP GOVERNOR AND PERFORMED AN ENGINE RUN UP AND FEATHER CHECK MULTIPLE TIMES, THE CHECK WAS GOOD. PROPELLER GOVERNOR WAS FOUND TO BE THE ISSUE.