When you’re experiencing electrical issues in your vehicle, it could be due to a faulty relay. A relay controls various electrical circuits in the car, from headlights to fuel pumps. If you suspect a problem with a relay, using a multimeter to test it is a simple and effective diagnostic method. In this article, we’ll guide you through the process of how to test a car relay with a multimeter.
Understanding the Car Relay A car relay is an electrical switch that opens and closes circuits to control the flow of current in various systems. It typically has five terminals： Pin 85 and 86： These are the coil terminals that control the relay. Pin 30： This is the common terminal that connects to the power supply. Pin 87： This is the “Normally Open” (NO) terminal, where the current is sent when the relay is activated. Pin 87a： This is the “Normally Closed” (NC) terminal, which is used in some relays and provides continuity when the relay is not activated. Now, let’s walk through the step-by-step process of testing your car’s relay using a multimeter.