What was found
NO DUCT PRESSURE WITH APU BLEED ON OUT GATE. GROUNDED - YES. REMOVED & REPLACED APU ENGINE WIRE HARNESS P/N 3888449-2, REF B737-900 AMM 49-11-01-400-802 & APU DATA MEMORY MODULE REF B737-900 AMM 49-72-11-400-801. OPERATIONS CHECK NORMAL. VERIFIED CORRECT APU PART NUMBER, SERIAL NUMBER, APU CYCLES, APU HOURS ARE CORRECT. ALSO, VERIFIED APU BLEED AIR PRESSURE (20 PSI). CYCLED APU NUMEROUS TIMES, APU BITE PROCEDURE REF B737-900 FIM 49-60 TASK 801 SHOWS NO CURRENT STATUS FAULT. NO FAULT HISTORY AND NO MAINTENANCE HISTORY.