What was found
ON CLIMBOUT ZONE TEMP LT CAME ON 180 CONT CAB SELECTED COOLER TEMP. ZONE TEMP LT STAYED ON. ABLE TO CONT TEMP IN CONT CAB WITH TEMP SELECTOR. WOULD NOT RESET WITH TRIP RESET BUTTON. LIGHT WENT OUT FINALLY 1 1/2 HOURS AFTER IT CAME ON. ON DESCENT LT CAME BACK ON. GROUNDED - YES. PERFORMED B737-800 FIM 21-62 TASK 801, NO FAULTS FOUND. INSPECTED CABIN TEMP SENSOR FILTER (FOUND CLOGGED) REPLACED CABIN TEMP SENSOR FILTER REF B737-800 AMM 21-61-06. OPS CKS NORMAL.