As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, PILOT NOTICED AN ELEC BURNING SMELL WHILE TESTING WINDSHIELD HEAT SYS. PILOT TRIED CYCLING SYS OFF & THEN BACK ON TO DETERMINE SOURCE OF SMELL. THE BURNING SMELL DISSIPATED & THEN RETURNED WHEN WINDSHIELD HEAT SYS WAS TURNED ON. THE PILOT LANDED WITHOUT INCIDENT. INSPECTION REVEALED LOOSE FASTENER AT WINDSHIELD HEAT CB, REPLACED CB & TIGHTEN FASTENER, PERFORMED OPERATIONAL CHECK OF WINDSHIELD HEAT. SYS CHECK WAS NORMAL.