2007 Patriot. Passenger high-and-low beam do not come on anymore, driver's side works normally. Both passenger and driver side headlights come off a single fuse, so there is power going there. My passenger side front turn signal is also sometimes not working, sometimes fine. I have replaced the bulbs, so I am thinking it is a loss of continuity in the ground wire, which is likely common to both the headlamp and the turn signal. But I don't know which wire is the ground. Is there a color code?