[tsubaki]

If I'm not mistaken all newer vehicles need a wire harness T connector to install trailer lights. These are usually $9-$39 depending on vehicle. If someone somewhat familier with adding trailer lights on older vehicles did it to the newer models it is likely to get the results you have. Check and see if you have this T connection, look under the truck where the main wire harness in the rear along the frame and trace the wire to the trailer lights. If so other problems exist, if not get one and install it (Walmart, etc).