What was found
ACFT LOST PRESSURIZATION ON CLIMB-OUT. PERFORMED OPS CHECK IAW 21-30-00 AND TEST FLEW AIRPLANE. COULD NOT DUPLICATE THE PROBLEM. AFTER SPEAKING WITH TECHNICAL ASSISTANCE AT MFG, CHECKED THE WEIGH-ON-WHEEL SWITCH LOCATED ON LT MAIN GEAR. FOUND A BROKEN WIRE IN THE WIRING BUNDLE. INSTALLED AN ENVIROMENTAL SPLICE AND OPS CHECKED THE SYS WITH NO DEFECTS NOTED. SUSPECT THE WIRE WAS MAKING INCONSISTANT CONTINUITY PUTTING THE ACFT INTO GROUND CONFIGURATION AND OPENING THE OUTFLOW VALVES IN FLIGHT.