Truck Repair: Cummins M11 engine, cummins m11, fuel gauge

Question
We have a 1998 IHC Cummins M-11.  When we turn the ignition switch off the engine keeps running, the hands on the RPM and MPH gauges go back and forth, the fuel gauge shows the correct amount of fuel in the tanks and the hand on the AMP gauge flickers  We have changed the ignition switch with the same results.  Any ideas?  Thanks!

Answer
Sounds like something is wrong with the ignition circuit.Like something back feeding the ignition.I would check pin A in the 23 pin connector for key switch power after you turn key off.If it has voltage that will confirm ignition circuit problem.If no voltage then on engine side,possible fuel shutoff solenoid problem.