how is it not working? are you not getting the full setup menu?
try this..
--> ignition must be on acc or on position
--> engage the parking brake
--> press and hold the foot brake + release the parking brake then re-engage
--> release the foot brake
full menu should show if your wires are tapped to the correct wires. the above steps must be done to also watch dvd's.
you can install a toggle switch instead of tapping into the parking brake so you can easily activate the menu or dvd function while the car is in motion.