Quickly spot bad relays before they cause issues. This tool helps you confirm if your relays are firing correctly, removing the guesswork when diagnosing electrical issues. Connect directly to the vehicle battery with the included clamps to verify whether the battery is charged and the alternator is producing the correct output. Our tools are built tough for any situation. Garages, workshops, and roadside toolkits, this tester is lightweight, portable, and engineered to last for years of reliable service. Just plug in the relay, hit the TEST button, and watch the lights tell you everything you need to know. No complicated setup, no advanced mechanic skills required. Hook up to your car battery with the heavy-duty clamps to see if your battery's holding a charge and your alternator is producing the correct output.