Installing factory tack in my 70 Dart rallye dash. I know the one wire goes to coil my question is where did they hook up the positive wire witch is supposed to be hot when key is turned on and where does the ground hook in at.wondering if they run to the back of fuse block where I see some connection points there? Haven't install dash back in car yet so have no power to check for a source.wanted to get this all hooked up before installing.