What was found
FLIGHT CREW OBSERVED LT WING FUEL TANK OVERPRESSURE ANNUNCIATOR INDICATION IN CRUISE FLIGHT. CREW FOLLOWED PROCEDURES IAW CHECKLIST AND INDICATION RETURNED. TROUBLESHOT SYS AND FOUND LT WING FUEL TANK OVERPRESSURE SWITCH OPERATION FAULTY. REPLACED SWITCH ASSY WITH NEW SWITCH ASSY AND FOUND SYS INDICATIONS NORMAL. RECOMMEND MFG INVESTIGATE IF THIS IS A FLEET PROBLEM, AND IF NECESSARY DETERMINE IF FAILURES LIMITED TO DESIGN OR LIMITED S/N RANGE SWITCH QUALITY ISSUE.