What was found
RT SIDE WINDOW OVERHEAT LT ILLUMINATED IN FLIGHT. DID QRH PROCEDURE. LT CAME BACK ON AFTER 4 MIN OFF. GROUNDED - YES. PERFORMED WINDOW HEAT CONTROL UNIT BITE PROCEDURE PER B737-900 FIM 30-41 TASK 801. FOUND WINDOW SENSOR FAULT MULTIPLE TIMES IN HISTORY. PERFORMED WINDOW TEMP SENSOR RESISTANCE MEASUREMENTS PER B737-900 AMM 30-41-21-760-801. RESISTANCE CHECK FAILED. FOUND TERMINAL ALREADY ON SPARE SENSOR. REMOVED AND REPLACED RT SIDE WINDOW PER B737-900 AMM 56-12-11, OPS CHECK GOOD.