Yes, I spliced into existing set or wires behind the taillights. Install was very easy, I solderer the spliced wires together and then used heat shrink to seal the wires.
Just installed my second set of OEM LED lights under the bed rail "truck came factory with one set". Also just got my truck back from installing a Line-X bed liner with sealer. Second set makes a huge difference and even outs the light in the bed.