I have a similar issue with this same speaker switch. I have replaced the Bose with a Marantz surround receiver and 5.1 Klipsch speaker system. The dash radio was set up in a way I can't exactly figure out. They had the DC dash radio running the front 2 AC Bose speakers and then if you turn on the external speaker switch, the dash radio ran what appear to be DC outdoor speakers. Now that the Bose is gone, the outdoor speakers do not work and the dash radio will not run any speakers inside. With the exception of the outdoor speakers, I found the existing speaker wires and ran them directly to the new Marantz amp which worked fine. I'm going to connect separate stand alone speakers in their own box to the dash radio for use while driving. I'd like to implement the external speaker switch and have it where I can switch between the inside speakers and the original outdoor speakers. In addition to the two sets of speaker wires that I think go to the outdoor speakers, there are two more connections on the switch with white wires that are also connected into some other wiring. I have no idea what those white wires could go to, or which connections do what on the switch. Maybe I'd be better off abandoning the switch and just running the outdoor speakers to the rear speaker connections on the dash radio and using the fader to select between inside and out? Any thoughts on this? I'd kind of like to have the original external switch working but it isn't a must.