i purchased a jvc double din tv/navi/dvd/mp3 etc. headunit and it works fine but i missed the info and maps from my stock nav, i tried to plug everything up to have it work with the new head unit and the stock nav plays the discs it comes with and gets power so does its controls but the screen gets none is there something im doing wrong or do i need to splice into any wires. any help would be helpful im still new at the mods on these cars thanks guys