What was found
MAINTENANCE FOUND FEEDER HARNESS BURNT WHILE TROUBLESHOOTING THE APU. A STRINGER AT BELLY OF AIRCRAFT ABOUT 15 INCHES FORWARD OF APU COMPARTMENT AFT OF AFT PRESSURE BULKHEAD WAS FOUND BURNED DUE TO THE FEEDER HARNESS ARCING. A NEW HARNESS WAS SPLICED IN AND RECEPTACLE D4800J WAS REPLACED. APU OPERATION CHECKED GOOD. THE BURNED SECTION OF STRINGER WAS REPAIRED IAW SRM 53-10-3, FIGURE 1, SHEET 7. A CONDUCTIVITY TEST WAS PERFORMED ON SURROUNDING FUSELAGE SKIN AND THE CONDUCTIVITY OF THE AREA WAS WITHIN LIMITS PER SRM 51-10-03.