Once you connect the Power Probe III to your car battery you will have access to an amazing variety of diagnostic functions. With the press of a switch you"ll have an instant hot lead or ground lead. Use the probe top and ground lead simultaneously to power up components right in your hand. Instantly check components for continuity as well as identify positive, negative and open circuits without re-polarizing hook-up clips. Locate shorts without wasting fuses. Once you connect the Power Probe III to your car battery you will have access to an amazing variety of diagnostic functions