Best Car Engine Relays of 2025

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Car engine relays are an essential component of a vehicle's electrical system. They act as switches that allow electrical current to flow through the engine's various components, such as the fuel pump, ignition system, and cooling fans. Without relays, the engine would not start or run properly. Car engine relays come in various types, including starter relays, fuel pump relays, and cooling fan relays. They are designed to withstand high temperatures and vibrations, ensuring reliable operation in harsh automotive environments. Regular maintenance and replacement of faulty relays can help prevent costly engine damage and ensure optimal performance.
At a Glance: Our Top Picks
Top 10 Car Engine Relays
Standard Motor Products RY-698 Engine Relay
The Standard Engine Relay, made in the United States, comes with a package height of 2.28 inches, length of 4.59 inches, and width of 3.27 inches. This relay is crucial for your car's engine system, ensuring smooth operation. With its compact packaging, it's easy to store and install, making maintenance hassle-free. The high-quality build of this relay guarantees durability and reliability, giving you peace of mind while driving.
Original Engine Management JR50 Main Relay
This car engine relay features brass or copper contacts that ensure low contact resistance, high-quality composite housings that resist harsh under-hood conditions, and O.E. type materials that ensure optimum performance and extended service life. It is designed for vehicle-specific fit.
Original Engine Management JR66 Relay
This multi-purpose relay is a product type of car engine relays with a package size of 3.555cm L x 4.064cm W x 7.302cm H and a weight of 0.85lbs. It is made in Taiwan.
BMW Relay
The BMW Relay is a genuine OEM (Original Equipment Manufacturer) product that provides quality engine effectiveness. With its direct fit feature, it ensures a perfect fit for your car engine. The package dimensions of 12.0 H x 15.0 L x 9.0 W (inches) make it suitable for universal fit. This relay is designed to make contact and comes in a stylish sky-blue color. The BMW Relay is not only reliable but also convenient for car owners. It ensures the efficient functioning of your engine, allowing you to enjoy a smooth driving experience. Whether you need to replace a faulty relay or upgrade your car's engine performance, the BMW Relay is a great choice.
Four Seasons Relay 35746
The Four Seasons Relay 35746 is an essential auto part designed to enhance your vehicle's engine performance. This product comes in a compact size, making it easy to install in various vehicles. Manufactured in China, it ensures quality and reliability for drivers. With its specific dimensions of 8.89 cm in length, 7.111 cm in width, and 5.08 cm in height, it fits well in tight spaces under the hood. Using this relay can help ensure that your engine operates smoothly, providing you with peace of mind on the road.
Standard Motor Products RY27 Relay
The Standard RY27 Relay is a compact and efficient component designed for car engine systems. With a height of just 0.3 inches, it easily fits into tight spaces under the hood, making installation hassle-free. Its length of 1.4 inches and width of 0.75 inches ensure that it doesn't take up unnecessary room, allowing for a neat setup. Originating from China, this relay is built to meet automotive standards, providing reliable performance for your vehicle. Choosing this relay can enhance your engine's electrical system, ensuring smooth operation and peace of mind on the road.
Four Seasons 35760 Relay
The Four Seasons Relay is designed to enhance the performance of your car's engine. With a compact size measuring just 2.63 inches in length, 2.44 inches in width, and 1.75 inches in height, it fits easily into tight spaces, making installation hassle-free. Weighing only 0.21 pounds, it adds minimal weight to your vehicle, ensuring that your engine operates efficiently without unnecessary burden. Its lightweight design also makes it easier to handle during installation or replacement, giving you convenience and confidence as you work on your vehicle.
JD2912 24V 40A Car Relay
The 通用 Car Relay Pack includes four 24V 40A SPST relays with sockets, making it a reliable choice for your vehicle’s electrical needs. Each relay is equipped with wires, ensuring easy installation and connectivity. These relays are specifically designed for use with LED indicators, which means you can enhance your vehicle's lighting system effortlessly. With compact dimensions of 1.57 x 1.18 x 1.18 inches, they fit conveniently into tight spaces, providing versatility in your car’s engine management system.
Four Seasons 35907 Relay
The Four Seasons Relay is designed specifically for your vehicle's needs. This part controls the A/C compressor, ensuring efficient cooling during hot days. It also operates the engine cooling fan motor, helping to prevent overheating and maintain optimal engine performance. Additionally, it manages the HVAC blower, providing you with a comfortable cabin environment. With its precise fit and reliable performance, you can enjoy peace of mind knowing that your vehicle's essential systems are running smoothly.
Four Seasons 36010 Relay
The Four Seasons 36010 Relay is a standard relay designed for car engines. It is a reliable and high-quality product manufactured by Four Seasons. With a part number of 36010, this relay is lightweight, weighing only 0.05 pounds, making it easy to handle and install. The package dimensions of 3.81 H x 6.096 L x 3.81 W (centimeters) ensure that it can fit into tight spaces in your vehicle. This relay is essential for the proper functioning of your car's engine, as it helps control various electrical components. It provides convenience and peace of mind, ensuring that your engine runs smoothly and efficiently. The Four Seasons 36010 Relay is a must-have for any car owner looking for a reliable and durable relay.
Frequently Asked Questions (FAQs)
1. Can I drive with a bad relay?
It is not advisable to drive with a bad relay. If the ignition relay fails while the engine is operating, it will cut off power to the fuel pump and ignition system, causing the vehicle to immediately stall due to the lack of fuel and spark.
2. Can a car run without relays?
No, a car cannot run without relays. The starter motor requires a significant amount of current, and without a relay to control it, it can burn out. Additionally, if the starting relay fails, the vehicle may not start at all.
3. What are the symptoms of a blown relay?
One common symptom of a failed ignition relay is a car that suddenly stalls while operating. If the ignition relay shorts, burns out, or fails, it will cut off power to the fuel pump and ignition system, leading to the engine shutting off.
During our car engine relay research, we found 24 car engine relay products and shortlisted 10 quality products. We collected and analyzed 2,793 customer reviews through our big data system to write the car engine relays list. We found that most customers choose car engine relays with an average price of $15.98.
The car engine relays are available for purchase. We have researched hundreds of brands and picked the top brands of car engine relays, including Standard Motor Products, ORIGINAL ENGINE MANAGEMENT, BMW, Four Seasons. The seller of top 1 product has received honest feedback from 385 consumers with an average rating of 4.7.

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.