Running a build, using stock wiring (each set of leads will only be carrying about 150watts max) to wire my highs on my 4 channel, but where do the leads terminate? Aftermarket harness has all 4 channels, but is that where they terminate? Or do those leads run back to amp then back up to highs? Amp wiring looks like it has more then enough leads to accept signal from headunit, amplify then go back out to highs. Is that how this stock setup works or can I go right from headunit area to all 4 channels?