Hi,
Single wire to hook up (apart from power & ground). Is a wire running into the harness that has the wires for power, acc on + speakers etc.
Been a while but I think it is blue & white? I just cut in before the OEM harness and spliced the PAC wire in. Failing that you could use a connector to plug into the harness
If you are using a scosche MI02B harness or something similar (why wouldn't you, simple & clean) then it is a wire leading in that the MI02B does NOT use
Confused? - hope not
Just checked a pic. Wire is navy with silver bands just next to or above orange wire. Can post a pic morrow if you need one