Testing a car relay with a multimeter is an essential skill for any car owner or mechanic. Relays are an integral part of many electrical systems in your vehicle, controlling functions such as the ignition system, lights, and cooling fans. When a relay fails, it can cause significant issues, including a car that won’t start or electrical components that won’t function correctly. Using a multimeter to test a car relay is an easy, efficient way to determine if the relay is functioning properly. This step-by-step guide will help you understand how to perform the test.

Why Testing a Car Relay is Important A relay is essentially a switch that is activated by an electrical current. When the current flows through the coil, it closes the circuit and powers various electrical components. Over time, however, relays can become faulty due to wear and tear, corrosion, or dirt, which can prevent the relay from switching correctly. If you suspect a problem with any electrical component in your car, testing the relay is a good first step before replacing expensive parts. What You’ll Need A digital multimeter (or an analog multimeter) A car relay (that you suspect is malfunctioning)