A. ### Importance of Relay Tester Most cars use relays for their headlights, windshield wipers, starters, air - conditioners, power seats, power windows, anti - lock braking systems, and audio systems. Automotive relays are affected by factors such as vibration, high temperature, low temperature, and humidity, which can shorten their service life. However, once a relay fails, it can cause system components to malfunction, and may even make the entire vehicle inoperable. Therefore, it is important to regularly check the relays in the car. The tester checks whether the relay contacts are working properly by connecting the car battery (11V - 15V) to the relay coil. B. ### Features 1. It is a testing tool for automotive relays. By continuously applying the car battery voltage (11V - 15V) to the relay coil, the detector can check the function of the relay contacts. 2. The tester can observe the contact data, closing time, relay inertia, etc. at each testing stage. 3. The test can control the opening and closing of the relay. 4. If the relay is abnormal, the red LED light will light up; if it is normal, the green LED light will light up. 5. It is well - crafted and has good performance. 6. It is easy to operate. 7. It is portable. 8. It is durable. C. ### Material Plastic and metal D. ### Color Black and red E. ### Voltage 12V F. ### Dimensions Approximately 110 * 60 * 28 mm G. ### Product Name Automotive Relay Tester One 12V Relay Tester H. ### Five Advantages 1. Safe and environmentally friendly 2. Good durability 3. High cost - effectiveness 4. Strong high - temperature resistance 5. Lightweight and elegant I. ### Precautions The car battery should be a 12V battery, and the voltage should be between 11 - 15V. The coil resistance should be at least 20 ohms. J. ### Usage Method The steps are as follows: 1. Connect the power lead to the car battery - connect the black alligator clip to the negative pole and the red alligator clip to the positive pole. 2. When the LED light on the tester lights up red, it indicates that the tester is powered on. 3. Check the relay before inserting it into the tester. If it is a 4 - pin relay, select “4 - pin” on the tester; if it is a 5 - pin relay, select “5 - pin”. 4. Insert the relay into one of the three sockets. 5. Press the “Test” button. 6. The tester will check the pin configuration of the unknown relay. If the unknown relay is different from most common automotive relays or the pins of the unknown relay are damaged, the tester may light up the red LED light. 7. If the pin configuration of the relay is correct, the tester will perform 10 opening and closing tests on the relay to detect the contact closing and opening times. If the time exceeds the limit, the tester may immediately light up the red LED light. 8. After 10 tests on the contact closing and opening times, the tester will check the consistency of the relay. If the test passes, the tester will light up the green LED light; if it fails, the red LED light may light up. 9. Disconnect the power lead from the car battery and remove the relay from the tester.