What was found
ZONE TEMP LIGHT FOR CONT CAB ILLUMINATED ON MASTER CAUTION RECALL. EXTINGUISHES ON MC RESET. GROUNDED - YES. RAN PACK TEMP CONTROLLER BITE REF B737-900 FIM 21-62 TASK 801 AND COULD NOT GET A FAULT TO POPULATE. SINCE THERE WAS PREVIOUS HISTORY OF THIS FAULT, CHANGED THE ZONE TRIM AIR MODULATING VALVE FOR THE FORWARD PASSENGER COMPARTMENT PRECAUTIONARY REF B737-900 AMM 21-61-21-000-801. LEAK CHECK GOOD. ALL GROUND VERIFICATION TESTS SUCCESSFUL. THIS CLEARS MEL 21-21G C/N 23025413 SEAMC WILL NOTIFIED.