Why you need this tester Quickly identify live circuits, blown fuses, wiring breaks, and poor grounds without guessing. The compact tester saves time on routine diagnostics for cars, RVs, and trucks and lets you work one-handed in tight spaces. Key features and benefits Steel probe tips: Easily pierce wire insulation for direct circuit access and accurate testing. Large alligator clip: Secure one-handed connection to battery or chassis ground and reach awkward or confined areas. LED test light: Illuminates when a circuit is live; brightness varies with the measured voltage so you can quickly judge signal strength. Wide voltage range: Tests automotive circuits from 6V to 24V, suitable for passenger cars, RVs, and trucks. Functions: Detects open circuits, fuses, taillights, headlights, turn signals, ground faults, shorts, and breaks in wires. Portable and durable: Lightweight, compact design for easy carrying and storage; steel probe construction for reliable durability. Practical use scenarios Roadside diagnosis: Clip to the battery or chassis, pierce the insulation on a headlight or taillight wire, and confirm whether the bulb is receiving power. Workshop troubleshooting: Quickly trace a short or open in a trailer or RV 12V system, testing fuses and individual circuits without removing panels. Fleet maintenance: One-handed testing of turn signal circuits and grounds on cars and trucks during routine inspections to speed up service checks. What to expect in operation Connect the alligator clip to a known ground or battery terminal, touch the steel probe to the wire or terminal you want to test, and observe the LED. A bright LED indicates a good/energized circuit; reduced brightness corresponds to lower measured voltage. The tool works across the common automotive voltage range of 6V–24V. Materials and compatibility Probe material: Steel for reliable piercing and contact. Clip: Large alligator clip for secure attachment. Compatible with: 6V, 12V, and 24V electrical systems found in passenger cars, RVs, and trucks. Compact, practical, and built for routine electrical checks without extra complexity.