[VetteVet]

If I might add.
The NSS just connects the two wires when it is closed by the pins on the shifting column shaft in the steering column. So it doesn't matter how the wires are plugged in.The two plug-ins are shaped different so they cannot be swapped. I believe the start wires are one above the other and the back-up light wires are at a 90 degree angle from each other.

What I like to do to see if the NSS is working is to jump the two purple wires in the connector to see if the starter will turn. Make sure the vehicle is in neutral or park.
If the starter turns then all the wiring, the ignition switch,the voltage, etc. is OK and the problem has to be in the NSS. If it doesn't spin then the problem must be in the wiring the solenoid or a connection, and further testing will be necessary. I use a paper clip or a cotter pin to jump the connector.