What would stop s G-III APU from starting?


discrepancy: occasionally APU Master on gives no L.O.P.   light. No crank..

Occasionally APU will crank to 20 percent, and then go to 19, 18, 17……




Three good starts.  Add trouble lights.  1 good start.  1 start to 20 percent.  Swap to aft ECU. Ready for starts

Access start switch. 33 milli ohms, consistent