How to Use a 12-Volt Circuit Tester
How to Use a 12-Volt Circuit Tester Power is supplied to a vehicle's engine ignition, electric door locks, alarm systems and other accessories by the 12-volt circuitry that runs throughout the vehicle. When a circuit fails, you will find that a 12-volt tester is an invaluable tool for locating the source of the problem. If you are a do-it-yourself auto mechanic who understands basic electrical circuits, you can verify the presence or the absence of electrical power in your vehicle quickly and confidently by using a 12-volt circuit tester. Things You'll Need 12-volt circuit tester Maintenance manual Instructions Turn on the vehicle's electrical power. The accessory position on the ignition switch powers up everything except the engine ignition circuit. To check the ignition's 12-volt wiring, turn the switch to the "On" position. Connect the ground clip of the 12-volt tester to a well-grounded source. The battery's negative terminal is the best...