As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L SIDE WINDOW HEAT OVERHEAT LIGHT ILLUMINATED DURING FLIGHT. OVERHEAT LIGHT REMAINED ON AFTER FOLLOWING CHECKLIST. GROUNDED - YES. ACCOMPLISHED B737-900 FIM 30-41 TASK 801. NO FAULTS. PERFORMED GENERAL VISUAL INSPECTION OF WINDOW. NO DEFECTS NOTED. INSPECTED SENSOR TERMINALS AND WIRES. NO DEFECTS NOTED. INSPECTED COILED CORD. NO DEFECTS NOTED. WINDOW HEAT OPERATES NORMALLY. OVERHEAT TEST PASSED. REF B737-900 AMM 30-41-00.