?【Continuity Tests & Signal Tests】Put the Autel powerscan circuit tester in Resistance mode, using the probe tip with chassis ground or the auxiliary ground lead, continuity can be tested on wires, switches, relays and diodes attached or disconnected from the vehicle electrical system. Signal Circuit Test can be useful when you extract a DTC from the vehicle and realize the cause might be kind of sensor circuit, testing your sensor and you will find the answer.?【Voltage & Polarity Tests】Autel auto circuit test probe kit provides step-to-step guides to help you easily complete your test work. In DC Voltage mode, contact the probe tip to a Positive circuit, the red LED will light and the LCD displays the voltage with a resolution of 0.1V. If contact the probe tip to a Negative circuit, the green LED will light and the LCD displays the voltage with a resolution of 0.1V. And you will hear different beeps when testing on different polarity.?【Following & Locating Short Circuits】In most cases, a short circuit will appear as a blown fuse or a tripping of an electrical protection device. Use this power scanner probe tip to activate and energize each of the fuse contacts. The contact which trips the circuit breaker is the shorted circuit. While Autel short finder probe can test for bad ground contacts instantly, allowing you to follow and locate shorts fast without wasting fuses.?【40ft Long Wiring, Bright LED Lights】Autel 汽车用品 electric tester comes with a 20feet long cable and another 20ft extension cable that allows you to make the initial connection directly to the vehicle's battery whether how large the vehicle/ tractor is, you can have easy accessibility to connect the trailer effortlessly to the rear of the vehicle. And on the top of the tester, there is a built-in flashlight, illuminate your work in dark or night, making you detect faults effectively.?【Universal for All 汽车用品s, 100% Worry-F.ree Purchase】Autel PS100 electric circuit test kit can work on all 6-30V cars, boats, trailers, ATV, motor homes and many other vehicles and machinery to power components such as radiator fans, starter motors, relays, window regulators, windshield wipers, etc. Autel electric tester is backed by 1 year qua.lity war.ranty, 30 days full re.fund/ new re.placement. If need any technical sup.port, we are here for you 7/24.