WTF does the relay wire go to? do i need that wire?

 

i hope im doing this rite... im wiring everthing to the harness, i have like 3 wires on the ground wire. i wire two wires togather that have a fuse, i think there yellow.

 

i have it all hook up with great sound, but wen i put a dvd in i can only here it and no video, it must have somthing to do with the ebrake ihave the bypass, but i want to hook it up the rite way for now becuas ei cant get the bypass to work...ffs... where do i install the green p brake wire to?

 

With some units you can simply ground the "parking brake" wire to make the DVD screen work. In others you need to cycle it between grounded and not and back to grounded, as if it were connected to the parking brake switch.