The one marked #2 (looking from the back side on the right) gets 12 volt all the time. you can jump from the big lug to it, the one marked #1 gets reduced voltage using a porcelain resistor that is only hot when the key is on. if you want to use a idiot light you will have to modify these instructions a little. if you want to use a gauge, the volt gauge is easy to wire in. An amp gauge is a little harder it wire up.