View Here : How To Test A Relay
Use a digital multimeter (DMM) to test the resistance between each pole of the relay and the corresponding NC and NO contacts for that pole. All NC contacts should read infinite resistance to the corresponding pole. All NO contacts should read 0 ohms to the corresponding pole.
Find the relay characteristics. The relay will have 4 pins; 2 will connect to the control circuit and 2 will connect to the high power load. Identify the relay as an ISO mini type. The International Standards Organization (ISO) defines this type of relay as 1 inch (2.5 cm) square (25.4 mm square).
How To Test the NC (Normally Closed) Terminal of a Relay. Take out a multimeter and place it in the ohmmeter (Ω) setting. Place one probe on the COM terminal and the other probe on the NC Terminal. Make sure that you read a resistance of near 0Ω. If you do, then the NC Terminal reads the correct resistance and should function properly.
Once you've identified the terminals, you need to check for continuity between the power circuit terminals. Set your digital multimeter to the lowest range on the Ohms scale or set it to 'continuity.'. Then, connect one lead to one of the power circuit pins, and connect the other lead to the other power terminal.
Step 11 - To test the trigger or primary side of the relay set up a test light by connecting a scribe to a test light clamp, being illustrated in the picture below while testing the tail light socket. Step 12 - Once the test light is set up connect each end to terminals 86 and 85.
How to test a car relay and how a car relay works. In this video we use a Ford relay and an Audi for examples. All you really need to do this is a multimeter set on resistance, however, a 12 volt ...
Probe the wire coming out of the relay and going to the component with the tip of the test light. If the bulb in the test light glows, there is voltage, and your relay is working properly. 4. Probe the wire or wires feeding voltage to the relay with the test light following the same procedure used on the previous step.