I wired up the lights that I installed in the stock tail box.
I procured some 4-wire, 22 AWG cable and 4-pin Deutsch connectors from
Amazon. Crimped and soldered the pins to the wire and assembled the connectors. Then soldered lights to the connector wires and routed to the area just forward of the tail light. I had to drill a hole in the front of the box and then one under the back lip of the seat to get the wire under the rear cover. I used Posi-tap connectors to splice into the brake light and turn signal wires.
Now I have extra brake lights on the back of the box and below the license plate, an extra tail light under the license plate, and extra turn signals on the back of the box. I commute on my bikes day and night so lights are a big deal to me.