I just bought this same head unit. The harness the head unit comes with has a few differ rca connections. There 2 sets for the front and rear speakers. A video input, a rear view camera input. And then a singular subwoofer output which requires a single male x dual female rca splitter. I've got all my amp wiring and head unit wiring all correctly installed, I even went as far as having my power wire on one side of my pickup and the rca cables on the other side. Anyways my amp powers on and the blue power light stays lit but there's no power whatsoever coming out of the speaker outputs going to my subwoofer? I think these head units are absolute garbage for the $300 I spent on it. I had a touchscreen dual headunit that worked better than this P.O.S