Alright I just installed the kvt-715dvd in my explorer and it doesn't work. Only thing I did not do is hook up the ground wire to the parking brake. Instead I used one ground for the whole unit. Now would this work or no? Now since this didn't work I tried to hook it up to the battery itself just to try to get it to work but got nothing. Any ideas? I have read somewhere about having to install a switch and flip it back and forth to get it to play dvds while moving but does the unit itself not work even if this ground isn't connected? Thanks for any quick help.