I hooked up the cars wire harness to the pioneers wire harness but realized there is another plug that went into the p913. When i tried without that plug with only the wire harness and the antenna plugged in, the pioneer got power but there was no sound. I took another look at where the wire harness was connected to and only saw 6 or 7 cables going to the wire harness when like 12 or so went through the connector to the pioneer. this other cable that must have to do with the speakers does not plug into the pioneer. Does anybody have any idea of how to make this work...? i'm stuck