I have a wiring diagram for the second generation TSX tech package that appears to have two wires coming from the stock head unit that provide the input to the stock amplifier. These two wires are labeled in the diagram as either "EL 8" or "EL S". There are two of these wires, one is also labeled "Data+" and the other "Data-".
I wonder if they are some kind of bus signal that allows the head unit to control the system at the stock amplifier.
Does anyone know what these wires do?