What was found
THE FLIGHT CREW REPORTED THAT THE LEFT WINDSHIELD WILL NOT HEAT UP PROPERLY. THE LEFT OVERHEAD TEMP CONTROL LIGHT WILL NOT ILLUMINATE IN ANY OPERATION. WHEN SYSTEM IS TURNED ON, THE CREW STATED THEY WERE NOT ABLE TO SEE THROUGH THE DISTORTED VIEW. ONLY A 3 INCH SECTION WAS HEATING. THE MAINTENANCE VENDOR REMOVED THE LEFT WINDSHIELD AND INSTALLED A NEW WINDSHIELD. OPERATIONAL CHECKS WERE SATISFACTORY. THE AIRCRAFT WAS RETURNED TO SERVICE.