You didn't state what vehicle we are working on but, most
fuse boxes have several free spades that are marked batt. . Take a test
light and check to see which ones are hot all the time and use a female
connector to attach the power wire to it. Make sure you run an inline
fuse to protect the circuit. If none of these are available they make a
connector that fits under the existing fuses to tap into that circuit.
Again use the test light to find the hot circuit.
