So I picked up a basic kenwood single din setup but I'm having issues wiring it up. I bought the 18 pin pac oem-1 harness for 07 g35 coupe and reading both manuals it looks like just match the colors and make sure it works. With the 18 pin, there are high and low (+) cables for the speakers that have no connection to the radio itself, so the white cable would be low and the white red cable would be high, I've tried splicing both white and white red to the radio from the harness with the 4 speakers and I hear nothing, you can barely faintly hear anything from the speakers. Also I noticed that my battery yellow cable has no power even with the car on and my ground black cable has no ground either. For now I have the yellow and red from the radio to my red switch cable for power, and my ground cable physically grounded to the body. I'm thinking it could be a ground, but where would the ground from this car lead to so I could check it? Or even the battery cable? I could use some advice