I recently bought an avic-f700bt but it didn't come with the RCA Harness. I've checked around and most places are 45-60bucks for the RCA harness. Can anyone help me out by telling me or showing me with a diagram or something which pins are for what. I only really need the Subwoofer preout for now. I have the RCA's from another old harness I can use to use on the Pins on the back of the unit directly.