Yes there is a 6 pin plug (see pic below) that connects the rear lights to the main wire harness. You can purchase a couple of 6 pin plugs (available at
Eastern Beaver) and make your own harness that fits between the OEM plugs. Make your harness with a branch off of it that goes to your new fancy light and you'll have successfully added your new light WITHOUT splicing into the OEM harness. You can easily restore the bike to OEM by simply removing your harness.
This is how I do ALL of my mods. You can see in the below picture that I have done just what I described above. This little harness was used to trigger the PC-8 fuse block AND add Hyperlites AND the LED you just purchased.
I installed the lights on the license plate. The Hyperlites went on the bracket that they sell and then I cut down a piece of aluminum to mount the KnightRider light too. I included two waterproof connectors to allow me to disconnect the lights when removing the fender. Both the Hyperlites and the Knightrider lights are controlled via an adjustable LED strobing modulator that is velcroed to the under side of the rear deck cover. The Hyperlights are both running and brake while I reserved the Knightrider to brake only. VERY noticable setup! More pics of the install (and all other mods to the NT) on my
photobucket site.