Originally Posted by
EuropeanAM
The addition of a Junction Adapter did not affect you being able to start the engine. Either it's not in neutral, the keyswitch is not connected, neutral safety wiring is disconnected, obviously lanyard not connected, or some other problem.
What you have unhooked and reconnected is a DISPLAY or INSTRUMENTATION connection only.
Note: The picture above appears to have the System Monitor's harness BACKWARDS (make sure gauge end is at the gauge, junction box end is at the junction adapter).
Make sure you have a terminating resistor on the engine-end of the system, also.