The one withe the space is 12V the stud next to the lable would be a ase gorund also. Tou need a insulator on the othe one top right in the photo, that is the - coil pretty sure. I might have one of those have toa look and see. I know I was insde one about a year ago and sold it. Might have another one . Sun tachs are the only ones I really play around with.