Wide application and overload protection The power circuit probe tester is made of ABS material, moisture-proof, high-temperature resistant and long lasting. It is suitable for diagnosing 6V–24V automotive electrical systems and can be used on cars, trucks, boats, trailers and motorcycles. It includes an overload protection device: when the current exceeds 8A, the internal circuit breaker trips and a buzzer sounds. Polarity test and continuity test Use the tester to check uncertain polarity in vehicles. When the probe touches the positive pole, the LED is red; when it touches the negative pole, the LED is green. It is also used to check the continuity of switches, relays, diodes, fuses and circuits. LED indicator and buzzer dual warning The tester provides an LED indicator and a buzzer for clear readings of grounding. A quick self-test ensures the tool is in good condition. When the current exceeds 7A, the tester automatically disconnects the current and emits a buzzer prompt to indicate a fault in the tested component. Tracking and locating short circuit Advanced high-sensitivity probes enable fast and accurate detection. This automotive test light saves time when troubleshooting car wiring, quickly locating the faulty wire and the fault point. Use scenarios - Diagnosing a dead or intermittent circuit in a car lighting or accessory system. - Locating a short or damaged wire in a trailer or boat wiring harness. - Verifying polarity and continuity when installing relays, fuses or switches.