I'm just a newbie here but I can tell you that you should look at the two points that are under that silver sticker that's on the bottom of the dash unit with some magnification. When I first tried to mod mine, one of the points shorted to the side foil and the thing died. Only the flip screen worked. I looked at the pc board with a 30x magnifier and saw the problem and then re-soldered and now it's fine. Don't forget to remove the light green wire from the brake switch and put to ground by itself.
Still a novice...old school, tv-tech