What was found
AT THE GATE, THE LEFT FWD WINDOW OVERHEAT LIGHT ILLUMINATED. FOLLOW QRH CHECKLIST AND LIGHT REILLUMINATED AFTER WAITING 3 MINUTES. ACFT GROUNDED. FRONT LEFT WINDOW HEAT CONTROLLER SHOWS SENSOR FAULT. SELECTED SENSOR SWITCH TO SPARE ALSO SHOWS SENSOR FAULT. TRIED WHCU NO HELP, IAW AMM 40-41-11. RANG SENSORS FROM LT WHCU D1044A PIN 13 T 26. RING BAD, OPEN, IAW FIM 30-41 TASK 812. REMOVED THE L1 WINDOW IAW AMM 56-11-11. MOVED L1 WINDOW WIRE TAP (1002-18) FROM TERMINAL1 TO TERMINAL 2 OF TB5010 IAW WDM 30-41-11 AND AMM 56-11-11 STEP H1. LEAK CHECKED AND OPS CHECKS GOOD.