I just purchased a 2015 with a blind spot and cross traffic indicator. When I hook up a trailer, the blind spot and cross traffic is disabled. I assume this is done when the trailer lights are plugged in. My question is, I have a dog box that will be permanently mounted in the bed. The box has all the lights that a trailer has. In the past I have gotten the power for the box from the back side of the trailer light plug. I think if I do it this way on this truck the blind spot indicator will be disabled and I really want it to work when I don't have a trailer hooked up. Anyone have any suggestions?