What was found
LEFT SIDE WINDOW OVERHEAT LIGHT ILLUMINATED IN CRUISE FLIGHT. LIGHT EXTINGUISHED AFTER TURNING OFF THE WINDOW HEAT FOR 5 MINUTES. LIGHT CAME ON AGAIN AT 4 HOURS 30 MINUTES INTO FLIGHT EXTINGUISHED AGAIN AFTER TURNING WINDOW HEAT OFF FOR 5 MINUTES. ACFT GROUNDED. PERFORMED B737-800 FIM 30-41 TASK 811. FOUND THAT BOTH PRIMARY AND SPARE SENSORS ARE OPEN, REF B737-800 WDM 30-41-12. ACCOMPLISHED AMM 56-12-11-400-801, STEPS 3.F.(6) & (7) K). REPLACED THE L2 SLIDING WINDOW. OPS TESTED GOOD IAW AMM 56-12-11.