THE OFFICE OF DEFECTS INVESTIGATION OPENED THIS PRELIMINARY EVALUATIONBASED ON A FLEET REPORT OF 3 THERMAL EVENTS ALLEGEDLYTHE RESULT OF CONDENSATION FROM THE AIR CONDITIONER'S EVAPORATOR DRAIN HOSE SHORTING ELECTRICAL CONNECTIONS AND VARIOUS ELECTRICAL COMPONENTS. THE INVESTIGATION WAS OPENED TO EVALUATE AND DETERMINE THE CAUSE OF THESE THERMAL EVENTS. A TECHNICAL EVALUATIONDETERMINED THAT THE DRAIN LINE FOR THE ROOFTOP EVAPORATOR UNIT CONTACTED THE BALLAST INVERTER FOR THE FLUORESCENT LIGHTING PANEL AND BECAME ABRADED.THE ABRASION OF THE DRAIN LINERESULTED IN LOW PRESSURE AND LOW VOLUMES OF MOISTURE BEING INTRODUCED INTO THE LIGHTING PANEL RESULTING IN ELECTRICAL SHORTS.NEW FLYER DECIDED TO CONDUCT A SAFETY RECALL TO CORRECT THE PROBLEM.THE CORRECTIVE ACTION WILL BE TO INSTALL AN ELBOW ON THE AIR CONDITIONING DRAIN LINE WHERE IT ENTERS THE BUS INTERIOR.THIS ELBOW RELOCATES THE DRAIN LINE TO PROVIDE THE NEEDED CLEARANCE BETWEEN THE LINE AND LIGHTING COMPONENTS.THIS REMEDY RESOLVES THE ISSUE UNDER INVESTIGATION AND, THEREFORE, THIS INVESTIGATION IS CLOSED.