We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Hardware

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Are the Best Tips for Relay Wiring?

By Paul Reed
Updated: May 16, 2024
Views: 11,891
Share

Relays are electronic switches used to power accessories or electrical systems in vehicles. A relay can be a solid-state integrated circuit, with no moving parts, but even in the 21st century many are reliable, inexpensive mechanical switches. They provide power to many systems without having to install heavy-duty wiring throughout the entire vehicle, which reduces cost and weight. Relay wiring can be improved by choosing good locations to place them, and providing adequate wiring size for the power needed by the accessories.

A typical relay looks like a small box, perhaps 1 inch (2.5 cm) on each side, with four connectors or pins at the bottom. Relay wiring is often installed in wiring blocks, where the relay plugs into sockets that match the pin shapes, and wires are connected from the sockets to the vehicle systems. This permits a part to be replaced easily if it fails by unplugging it and plugging in a new one.

The four pins on the bottom of the relay are often numbered, and each is connected to a different wire. One connects to the vehicle ground, which returns any unused power to the battery. One pin is connected to the switch, such as the ignition key, that activates the relay. The other two are connections to the battery and from the relay to the vehicle systems or accessories.

When drivers turn the key to start their car or truck, a signal is sent from the ignition switch, but the wiring may be quite thin. This is possible because the main power relay, which supplies the entire vehicle with power, is located in the engine compartment near the battery. The wire from the battery to the relay may be quite thick to supply all electrical needs, but the wire from the ignition key can be thin because its only purpose is to supply a small electrical current. When the key is turned, the current activates a switch inside the relay, and power from the battery flows to the vehicle through the relay wiring.

Installing relay wiring is not difficult, but some tips can help make the job easier. Placement is important so heavier wiring lengths are kept to a minimum, both to save money and reduce power losses. A wire taken from the battery positive terminal should be wired directly to the relay pin, and another to the accessory, using the shortest length of wire needed. This may place the relay closer to the battery or next to the accessory, depending on the vehicle.

The switch that controls the relay can be installed anywhere on the vehicle, with wiring supplied from an existing power source or another accessory power wire. Power requirements for the activation switch are small, so smaller wire sizes can be used and located in the vehicle as needed to hide them. Using a relay block for installing multiple units can make the job easier than wiring them separately.

Relay wiring is useful for extra lighting, louder horns that require additional power, or navigation systems. Using separate relays allows these systems to be operated separately from the vehicle ignition system. This reduces power loads on the ignition system wiring and can reduce electrical problems.

Share
EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
Share
https://www.easytechjunkie.com/what-are-the-best-tips-for-relay-wiring.htm
Copy this link
EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.