The 10 speaker JBL Synthesis system has speakers in place of the mirrors, my guess it that wiring is one of the speaker connectors.
i tried a mutlimeter to this. no such luck, no voltage even with the radio blasting.
any other ideas?????
If it is the harness connector for the rear JBL speaker option, which I think is right, you wouldn't expect to have any output on the connectors unless you had the JBL (or other radio system) which was able to connect to the rear harness. I believe that if you have the standard radio system, these wires are not connected to the radio at all, hense no output.
They are actually the connectors for the speakers. I know your photo does not show that same connector on the passenger side pillar but it should be there. It may just be lower in the pillar as both side in my limited with the JBL system have the same connectors.