Electrical Question

[KS72]

I have a 72 2 wheel custom camper with standard trans, which I recently changed the body out with a 71 Custom Deluxe. The new cab was setup for automatic trans I changed the steering column out using the original set up for standard trans, so I have standard trans but the cab has electrical harness for automatic. I ran a jumper to the harness plug that plugs into the neutral safety switch to get power to the starter, but jumping the harness plug to the backup lights runs a constant power supply to the backup lights when the ignition is turned on. I'm not sure if or how I need to bypass the nuetral safety plug to get my backup lights to work properly with the standard trans Any help would be greatly appreciated. Sincerely Ken