What was found
THE FRESH AIR DUCTING (P/N 111728-888) THAT SUPPLIES AIR TO THE REAR SEATS WAS ORIGINAL AND IN A TOTALLY UNUSABLE CONDITION. THE DUCTING COMES OUT OF THE FLOOR AT STA 133 AND RUNS UP THE SIDE OF THE DOOR FRAMES ON BOTH SIDES TO THE OUTLETS IN THE HEADLINER. WHERE THE STEEL WIRE IN THE DUCTING TOUCHED STRUCTURAL PARTS, IN THIS AREA, IT CAUSED DISSIMILAR METAL (ELECTROLYSIS) CORROSION. THESE PARTS WERE DESTROYED MAKING REPLACEMENT NECESSARY. SUBMITTER RECOMMENDATIONS: CAREFULLY INSPECT THE ROUTING OF THIS DUCTING AND REPLACE IT WHEN IT SHOWS ANY SIGN OF DETERIORATION.