The Hickok/Waekon Voltage Drop PRO, No. 78265, automatically tests vehicle wiring under load and measures voltage drop in the circuit. Displaying real-time loaded and unloaded voltage readings, users can switch modes to view readings from both sides of the circuit, pinpointing any excessive voltage drops. User selected current draw allows the component current to be simulated. Voltage Drop PRO won't blow fuses or damage computers. The Wiggle Test feature operates continuously, aiding intermittent signal drop out detection. Allows for 1-20 amp selectable current draw.