You must be talking about the backup lights under my bumper...there is an area there that isn't too think and I drilled through there. Those backup lights on the truck are powered through the center of the bargemen connector and turn on with the reverse switch like the regular backups. Backing up to a trailer in the dark...well - it isn't dark anymore.
The trailer backups are on a switch under the dash. When I have everything fired up you can see really well at night.