Best Circuit Opening Relays of 2025

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Circuit Opening Relays are electrical devices that play a crucial role in ensuring the safety of a vehicle's occupants. These relays are designed to cut off the fuel supply to the engine in the event of a collision or impact, preventing the risk of fire or explosion. They work by detecting the sudden deceleration of the vehicle and sending a signal to the fuel pump to shut down. Circuit Opening Relays are a vital component of any modern vehicle's safety system and are widely used in cars, trucks, and other vehicles around the world.
At a Glance: Our Top Picks
Top 10 Circuit Opening Relays
Mechanics Choice Relay for Toyota
The Mechanics Choice Relay is designed specifically for Toyota 4Runner, Camry, and Pickup models from 1983-1986 and 1989-1995. This relay offers a first-time fit, ensuring you won't have to deal with compatibility issues. It meets original equipment (OE) standards, meaning you can trust its quality and reliability. The relay is manufactured using superior materials, which enhances durability compared to the original parts. Additionally, it installs just like the factory unit, making replacement hassle-free. With rigorous inspections, you can be confident in its performance.
Toyota Circuit Opening Relay Assembly
The Toyota Circuit Relay is a genuine OEM part designed for a perfect fit in your vehicle. This factory original component ensures reliable performance, so you can trust it to operate effectively. You won’t have to worry about defects or poor craftsmanship, as it comes with a guarantee against such issues. Made in Japan, this relay emphasizes quality and durability, providing peace of mind for users who prioritize dependable automotive parts. With this relay, you can enhance your vehicle's efficiency and maintain its overall functionality.
Standard Motor Products RY276 Relay
The Standard Motor RY276 Relay is a high-quality circuit opening relay designed to provide efficient and reliable performance. With a package height of 4.19 inches, length of 9.9 inches, width of 6.19 inches, and weight of 5.37 pounds, this relay is compact and lightweight, making it easy to install and transport. The circuit opening relay is essential for controlling the flow of electricity in various automotive systems, ensuring smooth and safe operation. Whether you need to control the fuel pump, ignition system, or other electrical components, this relay delivers consistent and accurate performance. Its compact size and lightweight design make it a convenient choice for any automotive enthusiast or professional. With the Standard Motor RY276 Relay, you can rely on its superior quality and performance for all your circuit opening needs.
Standard Motor Products RY340 Relay
The Standard RY340 Relay by Standard Motor Products is a reliable circuit opening relay designed to enhance your automotive electrical system. With a package height of 4.19 inches, a length of 9.9 inches, a width of 6.19 inches, and a weight of 5.37 pounds, this relay provides efficient power distribution in your vehicle. The compact size ensures easy installation, while the sturdy build guarantees durability. This relay is essential for ensuring proper functioning of various electrical components in your vehicle, offering you peace of mind on the road.
Standard Motor Products RY31 Relay
This Standard Relay is designed for vehicle specific use and produced by Standard Motor Products. It has a compact size of 3.45" L x 1.81" W x 1.44" H, making it easy to install in tight spaces. This relay is ideal for use with Throttle Position Sensors, ensuring they can function correctly and reliably.
LVACODV 15016745 Headlight Relay
The LVACODV Headlight Relay is designed to enhance the performance of select Buick, Cadillac, and Chevrolet models. It effectively addresses issues with headlight beams and daytime running lights, ensuring your vehicle's lighting functions properly. Made from durable thermosetting plastic and a silver-copper alloy, this relay withstands high temperatures and electrical corrosion, providing long-lasting reliability. Its compact size allows for easy installation, optimizing your vehicle’s electrical system and boosting overall performance. With built-in safety features, you can trust that your vehicle is protected from potential electrical damage.
Standard Motor Products RY175 Relay
The Standard RY175 Relay is designed to enhance your vehicle's electrical system. With a compact package height of 3.1 inches, it fits easily into tight spaces, making installation straightforward. Its length of 3.63 inches and width of 3.2 inches ensures compatibility with various setups, allowing you to replace old or faulty relays with ease. Manufactured in Mexico, this relay promises reliability and durability, ensuring your vehicle operates smoothly. By using this relay, you can improve the efficiency of your circuit operations, providing peace of mind during your drives.
Standard Motor Products HR-106 Relay
The Standard Motor Relay is designed for reliable circuit opening applications. It measures 2.536 inches in height, making it compact and easy to fit into various setups. With a length of 9.841 inches and a width of 6.774 inches, this relay is packaged conveniently for storage or transport. Being manufactured in China, it offers a blend of quality and affordability, ensuring you get a dependable product without breaking the bank. This relay is ideal for those who need consistent performance in their electrical systems.
Standard Motor Products RY373 Relay
The Standard RY373 Relay is a reliable circuit opening relay that ensures your vehicle's electrical system operates smoothly. This essential component helps maintain the proper flow of electricity, which in turn protects your vehicle's circuits from overloads. By using this relay, you can enhance the overall performance of your vehicle's electrical systems, giving you peace of mind. With its durable design, the RY373 is built to last, providing you with consistent and long-lasting functionality. It's an important part that contributes to your vehicle's reliability and efficiency.
Standard Motor Products HR-125 Relay
The Standard Relay HR-125 is designed to provide reliable circuit opening capabilities. Originating from China, this product features a compact package height of 2.536 inches, making it easy to store or integrate into various applications. With a length of 9.841 inches and a width of 6.774 inches, it is also convenient to handle. These dimensions ensure that the relay can fit into tight spaces while maintaining optimal performance. This relay is an excellent choice for those needing dependable electrical components.
Frequently Asked Questions (FAQs)
1. How do relays open and close?
Relays function by opening and closing contacts in one electrical circuit to control another circuit. When a relay is not energized, a normally open (NO) contact remains open, and a normally closed (NC) contact remains closed.
2. How does normally open relay work?
Normally open relays default to an open position, meaning there is no contact between the circuits when they are not in use. When power is applied, an electromagnet pulls the first circuit into contact with the second, closing the circuit and allowing power to flow through.
3. What is an example of a normally open relay?
One example of a normally open relay is its use in blower motors. It can be used to delay the operation of a blower motor for a specific period after the activation of the heater unit, ensuring that the air is adequately heated before it is circulated.
4. Do relays fail open or closed?
Electromechanical relays tend to fail in the open position, while solid-state relays have a tendency to fail in a shorted state on their outputs. Although relays can fail in the opposite mode, these are the most common failure scenarios.
5. Why is open relay bad?
An open relay in the context of Simple Transfer Mail Protocol (SMTP) servers is improperly configured and allows unauthenticated relay of email. This can be exploited by spammers who connect to the server and send forged emails using the relay, leading to spam emails being sent.
6. What are the three types of relays?
The three main types of relays are electromechanical relays (EMR), solid-state relays (SSR), and Reed relays.
During our circuit opening relay research, we found 24 circuit opening relay products and shortlisted 10 quality products. We collected and analyzed 3,298 customer reviews through our big data system to write the circuit opening relays list. We found that most customers choose circuit opening relays with an average price of $52.17.
The circuit opening relays are available for purchase. We have researched hundreds of brands and picked the top brands of circuit opening relays, including Sawyer Auto, Toyota, Standard Motor Products, LVACODV. The seller of top 1 product has received honest feedback from 824 consumers with an average rating of 4.5.

Robert Reyes is a dedicated writer from San Francisco with a bachelor of degree in mechanics and a bachelor of degree in marketing. He focuses on making some complicated topics simple and enjoys explaining complex and technical things in an easy-to-understand way.