Can't get the lock screen to play. - Alpine CVA-1003 Car Video Player

You must hook up the brake wire in this case you'll be available to watch only when the brake is applied or if you want to avoid it, check the local law first about driving wile watching a video, usually in most of the states this is prohibited. After that if you'll like to unlock this is the way;
Just hook up the brake wire to ground (don't do the connection to the brake instead of, connect it to ground) and you will have unlocked the screen at all the times, but it is your responsibility because you may get a ticket for drive wile watching a video.