What was found
DURING CRUISE THE RIGHT SIDE WINDOW HEAT ILLUMINATED. RAN QRH PROCEDURES AND REILLUMINATED. GROUNDED - YES. T/S PER B737-900 FIM 30-41 TASK 811. TURNING ON WINDOW HEAT CAUSES OVHT LIGHT IMMEDIATELY. BITE CK OF WHCU INDICATES WINDOW SENSOR FAILED LAST TEN LEGS. PER THIS FIM REF, SWAPPED TO SPARE WINDOW SENSOR. PERFORMED WHCU BITE PER FIM 30-41 TASK 801, NO FAULTS. RIGHT SIDE WINDOW, WHEN WINDOW HEAT SWITCH TURNED ON "ON" LIGHT COMES ON. THIS CLEARS MEL 30-11E.