Oil Light stuck on

beyond frustrated. I cant seem to fix anything on this Dart. Removed the oil sensor, lucky I had a 1in socket, barely fit just enough to get it loose.
Put in the new one. farted around getting the wire terminal back on, as the new one has a slightly smaller spacing for the terminal to slide through.
Put the key in, one click to right light pops on right away. Even without engine started. I then started engine and it remains lit.
From what I can see tracing it from sensor to bundled wires, it is fine and not touching the car.

When I remove the wire from the sensor, the light goes off.
Any ideas for me?
If I can trace it to the bulkhead, how much resistance should I see of I use my multimeter?
I am hoping to avoid undoing all the tape and bundle if I can help it.

looks like it is a greyish wire BTW. thanks for all your ideas