What was found
LOW AIRFLOW FROM PACKS ON APU THE FLOW STARTS OUT NORMAL THEN DIES OFF. ACFT GROUNDED. PRESSURIZATION SYS GROUND TEST OK REF MM 21-31-00-700-802, NO FAULTS. BITE TEST OF NR 1 PZTC SHOWS EXIT FAULT ON AFT RAM AIR DOOR, NOT CYCLING, ALSO, THAT WOULD CAUSE THE LOW FLOW TO THE FLIGHT DECK. REF FIM 21-61, TASK 801. REPLACED LT EXIT ACTUATOR REF MM 21-51-27-400-801. FAILED STEP H 1-5. & ALSO NEEDS SEALANT ON BONDING JUMPERS STILL. TEMP SECURED ACTUATOR WITH MOUNT HARDWARE. ALL C/B'S ARE IN. REPLACEMENT RAM AIR EXIT ACTUATOR BAD FROM STOCK. REPLACED LT RAM AIR EXIT ACTUATOR. REF AMM 21-51-27/401. INSTALLATION TEST OF LT RAM AIR EXIT ACTUATOR PASSES. REF AMM 21-51-27/401. BONDING JUMPER SEALED. RAN PACKS, AIRFLOW DIES OFF. TRIM AIR VALVE INOPERATIVE, REF FIM 21-62/838, PRSOV, V146, REPLACED. REPAIR CONFIRMATION OF PRSOV PASSES. PACK AIRFLOW NORMAL.