What was found
(CAN) DURING CRUISE, RED LANDING GEAR UNSAFE LIGHT FLICKERING INTERNITTENTLY WITH A CORRESPONDING "CLUNKING" IN THE AIRFRAME FELT THROUGH THE COLLECTIVE STICK. UPON RETURN FROM FLIGHT MAINTENACE PUT AIRCRAFT ON JACKS AND THE LANDING GEARWAS OPERATED TO SIMULATE THE CONDITION. THE FAULT WAS TRACED TO THE LEFT MAIN DOWN LOCK WIRING HARNESS. THE HARNESS WAS REPLACED WITH A NEW ONE. THE SYSTEM WAS FUNCTION TESTED SERVICEABLE AND THE AIRCRAFT WAS RETURNED TO SERVICE.