WIDELY USED The car circuit tester is suitable for diagnosis in all 6V to 24V DC vehicle electrical systems. It can check switches, relays, and the on-off of diodes, fuses, and circuits, which can help you reduce diagnostic time in automotive electrical systems. POLARITY & CONTINUITY TEST This probe tester can help you quickly identify the positive and negative polarity of electric cables and plugs of vehicles. It can also test for continuity and do the jumper lead operation with the assistance of its auxiliary ground lead. TRACKING & LOCATING SHORT CIRCUITS The auto electrical tester uses advanced high-sensitivity probes to provide you with fast and accurate detection. Using the continuity tester can save a lot of time to troubleshoot the car wiring circuit, and quickly and accurately find the faulty wire and its fault point. COMPONENT ACTIVATION AND TESTING: This test light automotive circuit tester could activate components in and out of the vehicles electrical system, test and check the components if defective or not, or if the rating current of the component is higher than that of the circuit tester. HUMANIZED DESIGN The cable length of the short finder is about 13ft which allows you to access and test any electrical system easily. The LED indicator and buzzer warning can help you clear problems at a glance. Its clips with strong bite force which is not easy to fall off, provide you a better experience.