If things go like other vehicles I have installed a JoyCon into...
First, if you can probe the Green/Orange and the Green/Black wires to see if there is any voltage going to them with the car in acc/on. If not, continue.
I would then try to connect the black wire from the JoyCon EX into Green/Orange coming from the car and the white wire from the JoyCon EX into the Green/Black wire from the car.
Harness Data: http://pac-audio.com/swixprogramming...ehicles&ID=215
Give it a shot I suppose, let us know.