Do it yourself
Frequently asked questions about cars and motorcycles
Car tutorial (Do it yourself) Motorcycle tutorial (Do it yourself) Frequently Asked Questions

How a relay works

Model: (Various brands) Various
Part: Fuse box

The relay is an electric switch, and it is the simplest way to allow a low-power circuit to control the on and off operation of a high-power circuit. Its function is to physically and electrically separate the two circuits. The relay shown in the video is monostable, meaning it remains "energized" only as long as the coil is powered, and it consists of two distinct parts: the control circuit, which is a coil of copper wire wound around a core of iron. When a voltage is applied to its terminals, the coil becomes "energized," and the electricity flowing through the coil generates a magnetic field, turning it into a magnet. The power circuit, on the other hand, consists of a movable metal armature, a spring, and fixed contacts. When the coil is not powered, the spring holds the armature up, interrupting the circuit. When the coil is powered, the magnetic field generated by the coil pulls the armature down, closing the contact, and current can flow.

Posted on 19 December 2025 by ScegliAuto

Video tutorial

Related tutorials

How the Scooter Starter Relay Works
How the Scooter Starter Relay Works
(Various brands) Various In this video tutorial, you will learn how the starter relay of the scooter works. First, you should know that this type of relay can be found in the…
How to test a relay without tools
How to test a relay without tools
(Various brands) Various If you need to test a relay in your car without a multimeter, a YouTuber demonstrates a simple and practical method that allows you to check if the r…
How to test a car relay with a multimeter
How to test a car relay with a multimeter
(Various brands) Various The relay, like the fuse, is an electrical component used in cars to control the power loads of certain components. In today's video, we will see how…

    Frequently Asked Questions

    • Vari - Where is the fuse box located on the Vespa GTS 125? Read answer
    • Vari - What is the "WSW" fuse? Read answer
    • Vari - What is the front wiper fuse? Read answer
    • Vari - Where are the fuses located on a Ligier X-Too? Read answer

How to Open the Bonnet on the Lancia Y

To open the bonnet on this vehicle, follow these simple instructions: first, open the driver's door and locate the lever positioned just below the dashboard, marked with an image of the vehicle with the bonnet open. Pull this lever towards you until you hear a "click" indicating the bonnet is released. Next, exit the cabin and stand in front of the bonnet to disengage the safety catch and complete the opening. To do this, slightly lift the bonnet, locate the yellow lever underneath, and pull it to the left to fully release and open the bonnet.

Watch the video!


by ScegliAuto

More videos