As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WINDOW HEAT LEFT/SIDE WINDOW OVRHEAT. QRH 3.6 OVERHEAT DID NOT GO OUT. GROUNDED - YES. ACCOMPLISHED B737-900 AMM TASK 30-41-00-420-801 AND SWAPPED WIRE TO SPARE SENSOR FROM PRIMARY. ACCOMPLISHED BIT/VERIFY ON WINDOW HEAT CONTROL UNIT AND NO FAULTS WERE FOUND. ALL GROUND VERIFICATION TESTS SUCCESSFUL.