What was found
OWNER COMPLAINED THAT PILOT'S WINDSHIELD HEAT WAS INOPERATIVE. ICE WOULD BUILD UP ON WINDSCREEN WHEN HEAT SELECTED TO ANTI-ICE. THERE WAS NO FAILURE INDICATION PRESENT IN THE COCKPIT. CONFIRMED THE WINDSHIELD WAS NOT HEATING IN THE HANGAR USING INFARED IMAGING. WINDSHIELD RESISTANCE CHECKED AT THE CONTROLLER. WINDSHIELD WAS GETTING 28 VOLTS WHEN WIRING PROBED AT WINDSHIELD. REMOVED COCKPIT HEADLINER TO ACCESS TERMINAL BLOCKS FOR FURTHER TROUBLESHOOTING. FOUND POWER A POWER WIRE FOR WINDSHIELD EXHIBITING OVERHEATING AT SPLICE. INSULATION ABOVE HARNESS ALSO EXPOSED TO HIGH TEMPS. IT IS POSSIBLE THAT A FIRE COULD HAVE ENSUED AT SOME POINT BASED ON VISIBLE EVIDENCE OF LOCALIZED HEAT. REPLACED WIRING BETWEEN WINDSHIELD POWER SPLICES AND TERMINAL BLOCK AND SECURED AS NEEDED.