Want to disconnect GPS audio and add an AUX input.

[DingleB4rry]

Is it possible to disconnect the audio from the GPS (remove the wires from the harness) and somehow add in wiring for an AUX input? I have the GPS, Rear DVD, and Bose 6 disc CD changer. From what I can see there are no options for this model since it has no Sat radio input. I don't use the GPS (Google Maps works better) but need the screen to see my heater/AC and radio menus and such. But I don't need the audio from the GPS. I can't find the schematics for the harnesses online anywhere.

The head unit model # is 28185 EA600 if needed.

Thanks