What was found
ECON COOL VLV LT PACK ECONOMY COOLING VLV NOT IN COMMANDED POSITION. PERFORMED AIR ON TEST IAW FIM 21-52-811. VLV RESETS AT BEGINNING OF TEST BUT FAILS DURING ECON VLV OPERATION. IAW NEW VALVE 646-0029. REPLACED VLV IAW AMM 21-52-31 NEED TO ACP LEAK & OPERATION CHECKED ITEM G MR21565 OFF - 37 & ON - 67. PERFORMED CTCS SYSTEMS TEST, FAULT STILL PRESENT. REPLACED VLV, NO HELP. NEED FURTHER TROUBLE SHOOTING. REPLACED LT ECON COOL VLV IAW AMM 21-52-11, SYSTEM & OPERATIONS TEST PASSED.