Features:1.Introduction: P55 automotive electrical system activator for 12-24V automotive power circuit diagnosis, compact design, powerful, with reverse connection and overload protection, the tool probe can be used to test the conductivity and positive and negative detection, activation components and other functions, can quickly detect short circuits, broken wires or poor contact in the vehicle electrical system components, which helps the user faster and more accurate understanding of the vehicle problems, is an efficient and advanced test tool, can greatly improve the efficiency of the user's work.2.Positive and negative pole detection: When the device is connected to the vehicle power supply, the illumination will light up white and when the probe is touched to the positive circuit, the device will light up red.The device will light up green if the probe touches the negative circuit. 3.Component activation:The activation function can be used to activate components such as the starter fuel pump,solenoid, blower, cooling fan, headlights, etc.4.Continuity testing: By using the probe tip and auxiliary ground wire. Continuity tests can be performed on wires and components that are disconnected from the vehicle's electrical system. The unit will illuminate green when the continuity test is passed. (Note: Do not press the activation switch during the continuity test.)5.Grounding detection: Use the probe to make contact with the negative terminal of the component and the device will light up green when the ground test is passed. (Note: Do not press the activation switch during ground detection.)6.Test trailer lights and connectors: Connect the device to the battery, clip the clip of the auxiliary ground wire to the trailer ground, connect the probe to the socket of the trailer connector, and press the (-) button to detect the function and direction of the trailer light.7.Jumper lead function: Black clip and auxiliary ground wire directly connected through the device, the red clip and vehicle battery disconnected, the device can be used as a long jumper lead, (note that when the device is used for jumper function, please pay attention to avoid short circuit and overload, jumper lead function is not protected by the device circuit breaker).8.Track and locate short circuits in most cases, a short circuit will manifest itself as a blown fuse or a tripped electrical protection device (such as a tripped circuit breaker). Trace and locate the short circuit as follows: Remove the blown fuse from the fuse box; touch each fuse contact with a probe; trace the harness by noting the number or color of the wire and following it as far as possible. If you are tracing the brake light short circuit, first the sa find the color or number of the wire and mark it. If the device lights up green, you have verified that the wire is shorted, so be careful to cut the wire and touch each end of the wire with the probe. Follow the wire until the exact location. Repeat this procedure in the direction of the short circuit until you find the exact location of the short circuit.ParametersItem name: Automotive Electrical Circuit TesterModel: P55Supply voltage DC: 12-24VOperating current: 80mA Activation current: 0-8AOperating temperature: 0-60CStorage temperature:-40-70CCable length: 4MWeight: approx. 210gWhat you get: Automotive Electrical Circuit Tester. User manual. Carton package. Note:Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. Return Policy All of our items come with a 30-day free return policy. If you need to return, please contact us, let us know the detailed problem and send us some pictures for confirmation. We reserve the right to refuse any returns for objective reasons. Shipping Policy All of our items are shipped free with tracking numbers. Orders will be shipped within 3 working days upon receipt of payment. Most orders will be shipped within 1 working day. In most cases, shipping takes 8-12 working days.