Importance of Relay Tester Most automobiles use relays for lights, wipers, starters, air conditioners, power seats, power doors and windows, anti-lock brakes, stereos, etc. Automotive relays are affected by vibration, high temperature, low temperature, humidity, etc., which will reduce their lifespan. However, once the relay fails, it will immediately paralyze system components and even render the entire vehicle unusable. Therefore, it is very important to check the relay in the car regularly. The tester connects the car battery (11V--15V) to the relay coil and checks whether the relay contacts are working properly. Features: Automotive relay test tool. 1. By connecting the continuous car battery (11V-15V) to the relay coil, the detector can check the contact function of the relay normally. 2. The tester observes contact data, closing time, relay inertia, etc. during each test phase. 3． Test for correct control of relay opening and closing. 4. The red LED lights up when the relay is abnormal, and the green LED lights up when it is normal. 5. Fine workmanship and good performance. 6． Easy to operate. 7. Easy to carry. 8. Durable. Description Material: Plastic and Metal Color: Black and Red Voltage: 12V Dimensions: Approx. 110 * 60 * 28mm Product name: Automobile relay tester 1 x 12V relay tester Five high advantages: 1. Safety and environmental protection 2. Good durability 3. High cost performance 4. Strong temperature resistance 5. Lightweight and generous Note: The car battery must be 12V Battery voltage must be between 11-15V. The coil resistance is preferably at least 20 ohms. How to use this tool? The steps are as follows 1. Connect the power cord to the car battery - the black alligator clip connects to the negative terminal and the red alligator clip connects to the positive terminal. 2. When LED 3 lights up red, the tester is powered. Check the relay before plugging in 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" on the tester. 4. Plug 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 if the pins of the unknown relay are damaged, the tester will light up the red LED. 7. The tester will open and close the relay 10 times to test the contact closing and opening times for correct pin configuration of the relay. If the time expires, the tester will light up the red LED immediately. 8. The tester checks the relay for consistency after testing the contact closing and opening times ten times. The tester will light up the green LED if the test passes, and the red LED if it fails. 9. Disconnect the power cord from the car battery and remove the relay from the tester.