As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L-1 WINDOW HEAT INOP. GROUNDED - YES. PERFORMED WINDOW HEAT CONTROL UNIT BITE CK REF B737-900 FIM 30-41 TASK 801 AND L-1 CONTROLLER FAULTS WINDOW SENSOR. PERFORMED FIM 30-41 TASK 812 AND SWAPPED TO SPARE SENSOR AND FAULT CLEARED, BAD SENSOR MARKED AS INOP.