Yes, since you have an 03, stay with that schematic. I attached both range sensors (neutral safety switch) below. They were the same, but I don't know if the new plug is pinned differently. When you place the vehicle in park or neutral, there should be no continuation of power. Those two positions don't signal anything. They create an open circuit. Something leads me to believe you have no power to that switch.
Both model years receive power via a red wire with a white tracer. Do you have power to that wire? If you do, when you shift to reverse, drive, 1, or 2, power is transferred through the switch to the appropriate circuit.
Check to confirm power, and then check the output from the switch. When in park or neutral, there should be no power out.
One question. Did the original harness have the blue wire for drive?
Let me know what you find.
See pics below.
Images (Click to enlarge)
Saturday, August 28th, 2021 AT 10:00 PM