Best Automotive Engine Relays

What are the best automotive engine relays? We’ve tested and reviewed the top options to help you find the perfect fit for your car, truck, or boat.

Automotive engine relays are essential components that keep your vehicle running smoothly. They control power to critical parts like starters, fans, and fuel pumps, ensuring everything works when you need it.

Choosing the right relay can save you time and money. We’ve tested and reviewed the best options to help you find the perfect fit for your car, truck, or boat.

List of Top 10 Automotive Engine Relays

Title	Best For	Price
4 PCS Relays, 5 Pin Relay, 40A Waterproof Car Relays, 12V Relay Switch	These 40A waterproof car relays are perfect for anyone who needs reliable, durable, and easy-to-install relays for their vehicle or electric project. Whether you’re fixing a car, boat, or motorcycle, these relays are built to last and work in any weather.	View on Amazon (paid link)
(Pack of 4) High Power 4-Pin Fuse Box Relay 13500114/8385 – 12V 40A	This 4-pack of high-power relays is perfect for GM owners who need reliable replacements or backups. It’s easy to install and works for many car parts, like AC compressors and headlights.	View on Amazon (paid link)
HELLA 933332541 Relay, Main Current – 12V – 4-pin Connector	This HELLA 933332541 Relay is perfect for anyone needing a reliable, durable, and easy-to-install solution for their vehicle’s electrical system. It’s ideal for drivers who want consistent performance in any condition.	View on Amazon (paid link)
Gebildet 2pcs 12V 40A 4 Pin SPST Car Relay Harness JD1912, 12AWG Harness Sockets with Built-in Diode for Automotive Truck Van Boat Motorcycle	This product is perfect for anyone who needs reliable and durable relays for their vehicle. Whether you own a car, truck, van, boat, or motorcycle, these relays with built-in diodes will protect your electrical components and ensure smooth operation.	View on Amazon (paid link)
2-Pack 56055667AA Engine Cooling Fan Relay Compatible with Jeep Wrangler	This 2-Pack 56055667AA Engine Cooling Fan Relay is perfect for Jeep Wrangler owners who need reliable cooling system parts. It’s ideal for 2009–2016 models, offering easy installation and durable performance.	View on Amazon (paid link)
Hugwits 4 PCS 4 Pin 12V 30A Car Starter Relay, Multi-Purpose Waterproof Heavy Duty Standard Relays, Car Engine Relays Replacement Parts, Universal for Most Cars (Black)	This 4 PCS 4 Pin 12V 30A Car Starter Relay is perfect for car owners who need a reliable, waterproof, and heavy-duty replacement part. It’s ideal for anyone looking to fix engine starting issues or upgrade their vehicle’s electrical system.	View on Amazon (paid link)
PACLVIO 4Pcs 5 Pin 12V 30A Car Starter Switch, Multi Purpose Auto Fuel Pump Relay, High Performance Waterproof Stable Universal Relay for Car Motor Automotive Replacement Accessories	This PACLVIO 4Pcs 5 Pin 12V 30A Car Starter Switch is perfect for car owners who need a reliable and easy-to-install replacement for their auto fuel pump relay. It’s great for DIY repairs and works well in tight spaces.	View on Amazon (paid link)
Weasch 10 Pack Style 12AWG Relay Socket, 12V DC 5-PIN SPDT, Interlocking Relay Socket Harness Base with Wires	DIY car enthusiasts and mechanics who work on car electronics will love this relay socket. It is perfect for setting up door locks, warning lights, and truck circuits.	View on Amazon (paid link)
Relay 28300-10020, 12V 4 Pins Purple Starter Relay 28300-10020 156700-0503 – Compatible for Toyota Camry Corolla Lexus Various Models	This starter relay is perfect for Toyota and Lexus drivers with Camry, Corolla, or similar vehicles. It is ideal for anyone needing a simple, reliable replacement.	View on Amazon (paid link)
Nilight 50003R Automotive Set 5-Pin 30/40A 12V SPDT with Interlocking Relay Socket and Wiring Harness-5 Pack, 2 Years Warranty	This set is perfect for DIY drivers, off-road fans, and auto experts who need a fast, clean way to wire LED light bars and other accessories.	View on Amazon (paid link)

Detailed Reviews

Discover the top 10 Automotive Engine Relays handpicked for reliability and performance. Each product is expert-reviewed and backed by customer feedback, ensuring you get the best value. Whether you need durability, easy installation, or affordability, this guide has you covered. Find the perfect relay to keep your vehicle running smoothly and efficiently.

1. 4 PCS Relays, 5 Pin Relay, 40A Waterproof Car Relays, 12V Relay Switch

Upgrade your vehicle with 4 PCS Relays, designed for 12V systems and 40A capacity. These 5-pin relays are waterproof and durable, perfect for cars, motorboats, and more.

Easy to install, widely applicable, and built to last. Ideal for taillights, fans, pumps, and starters.

Pros	Cons
40A power handles demanding vehicle electrical systems. IP67 sealing keeps relays working in damp spaces. PA66 housing improves heat resistance and long service life. Five-pin design enables quick, tool-free wiring and replacement. Four-relay set offers flexible options for many vehicle needs.	No mounting hardware included, may need extra parts for setup. Limited compatibility with non-standard or older vehicle models. No instructions provided, might confuse first-time installers.

Perfect For:

These 40A waterproof car relays are perfect for anyone who needs reliable, durable, and easy-to-install relays for their vehicle or electric project. Whether you’re fixing a car, boat, or motorcycle, these relays are built to last and work in any weather.

Ready to Purchase?

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2. (Pack of 4) High Power 4-Pin Fuse Box Relay 13500114/8385 – 12V 40A

Upgrade your vehicle’s electrical system with this pack of 4 high-power 4-pin fuse box relays. Designed for 12V 40A applications, these relays are OEM quality and fully compatible with GM models.

Versatile and reliable, these relays power AC compressors, fans, headlights, and more. They’re built to last in harsh conditions, resisting heat, wear, and corrosion. Compact and easy to install, they fit tight spaces with hassle-free wiring.

Save money with this value pack of 4 relays. Perfect for replacements or backups, they offer unbeatable performance at a great price. Directly replace GM parts and keep your vehicle running smoothly.

Pros	Cons
Direct GM replacement – Fits Buick, GMC, Cadillac, and more. Powers multiple systems – AC, lights, fuel pumps, and more. Built to last – Resists heat, wear, and corrosion. Easy DIY install – Compact design, hassle-free wiring. Great value pack – 4 relays at an unbeatable price.	Not a guaranteed fit for every GM vehicle. 40A rating may not suit heavy-duty accessories. Requires a matching 4-pin socket and proper wiring.

Perfect For:

This 4-pack of high-power relays is perfect for GM owners who need reliable replacements or backups. It’s easy to install and works for many car parts, like AC compressors and headlights.

Ready to Purchase?

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3. HELLA 933332541 Relay, Main Current – 12V – 4-pin Connector

The HELLA 933332541 Relay is a 12V main current relay with a 4-pin connector. It ensures reliable performance for your vehicle’s electrical system.

Its durable design works well in extreme conditions. It also offers noise protection to keep sensitive systems safe.

Easy to install, universal fit, and dependable—this relay is a smart choice for modern vehicles.

Pros	Cons
Reliable switching for dependable vehicle electrical systems. Durable design works in extreme conditions. Noise protection keeps sensitive systems interference-free. Easy installation with standardized connectors. Universal fit for seamless integration with modern vehicles.	Connector fit may not match every vehicle. Wiring mistakes can cause damage or failure. Load limits require careful checking before use.

Perfect For:

This HELLA 933332541 Relay is perfect for anyone needing a reliable, durable, and easy-to-install solution for their vehicle’s electrical system. It’s ideal for drivers who want consistent performance in any condition.

Ready to Purchase?

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4. Gebildet 2pcs 12V 40A 4 Pin SPST Car Relay Harness JD1912, 12AWG Harness Sockets with Built-in Diode for Automotive Truck Van Boat Motorcycle

The Gebildet 2pcs 12V 40A 4 Pin SPST Car Relay Harness is a reliable solution for your vehicle’s electrical needs. It comes with 12AWG harness sockets and a built-in diode for added protection. This product is perfect for cars, trucks, vans, boats, and motorcycles.

Each relay has a built-in diode that protects your electrical components from voltage spikes. It also features high sensitivity and low power consumption, making it efficient and durable.

With a life expectancy of 100,000 electrical operations and 10,000,000 mechanical operations, this relay is built to last. Its compact size and easy installation make it a great choice for any vehicle.

Pros	Cons
Built-in diode protects your vehicle’s electrical system from damage. Compact design saves space in your car, truck, or boat. Long-lasting with 100,000 electrical and 10,000,000 mechanical operations. Low power consumption ensures efficient and reliable performance.	No waterproof design, limits outdoor use. Requires basic wiring knowledge for installation. Not suitable for high-voltage applications.

Perfect For:

This product is perfect for anyone who needs reliable and durable relays for their vehicle. Whether you own a car, truck, van, boat, or motorcycle, these relays with built-in diodes will protect your electrical components and ensure smooth operation.

Ready to Purchase?

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5. 2-Pack 56055667AA Engine Cooling Fan Relay Compatible with Jeep Wrangler

Get two fan relays in one pack. They fit Jeep Wranglers from 2009 to 2016.

They replace parts 56055667AA and 56055667AB. They send power to the engine cooling fan. Their strong build stands up to heat and shake.

Each relay has a direct-fit design. You can swap it in with no changes and keep the other as a spare.

Pros	Cons
2 Relays for your jeep Easy install in minutes Fits jeep wrangler 2009-2016 Strong parts for hot days Great value for fans	Limited vehicle compatibility, only fits Jeep Wrangler 2009–2016. No installation tools included, requires separate purchase. Not universal, may not work with other vehicle models.

Perfect For:

This 2-Pack 56055667AA Engine Cooling Fan Relay is perfect for Jeep Wrangler owners who need reliable cooling system parts. It’s ideal for 2009–2016 models, offering easy installation and durable performance.

Ready to Purchase?

View Price on Amazon (paid link)

6. Hugwits 4 PCS 4 Pin 12V 30A Car Starter Relay, Multi-Purpose Waterproof Heavy Duty Standard Relays, Car Engine Relays Replacement Parts, Universal for Most Cars (Black)

Hugwits 4 PCS 4 Pin 12V 30A Car Starter Relay, Multi-Purpose Waterproof Heavy Duty Standard Relays, Car Engine Relays Replacement Parts, Universal for Most Cars (Black)

Use it when your car will not start. This 4-pin, 12V 30A relay fits many cars and trucks. You get four relays for repairs or backups.

The tight seal blocks water and dust. The strong body works with fuel pumps, fans, and other car parts.

The standard fit makes swaps simple. It can help fix your car’s electric parts. Check the pin shape and power needs before you put it in.

Pros	Cons
Universal fit for most cars and trucks. Waterproof and heavy-duty for tough engine conditions. Multi-purpose use for starters, pumps, and fans. Easy replacement for worn-out parts. 4-pack offers backup or multi-circuit use.	No installation tools or instructions included, may need extra help. Limited to 12V systems, not suitable for higher voltage vehicles. Bulk purchase, might be more than needed for single repairs.

Perfect For:

This 4 PCS 4 Pin 12V 30A Car Starter Relay is perfect for car owners who need a reliable, waterproof, and heavy-duty replacement part. It’s ideal for anyone looking to fix engine starting issues or upgrade their vehicle’s electrical system.

Ready to Purchase?

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7. PACLVIO 4Pcs 5 Pin 12V 30A Car Starter Switch, Multi Purpose Auto Fuel Pump Relay, High Performance Waterproof Stable Universal Relay for Car Motor Automotive Replacement Accessories

PACLVIO 4Pcs 5 Pin 12V 30A Car Starter Switch, Multi Purpose Auto Fuel Pump Relay, High Performance Waterproof Stable Universal Relay for Car Motor Automotive Replacement Accessories

PACLVIO 4Pcs 5 Pin 12V 30A Car Starter Switch is a high-performance, waterproof relay for your vehicle. It’s made with durable nylon and brass pins for reliable quality. Use it to control high-amperage loads safely in your car.

This relay works for fuel pumps, cooling fans, and more. It’s easy to install and fits in tight spaces. Buy with confidence knowing it’s professionally made.

Pros	Cons
High-quality nylon shell for durability and waterproof performance. Easy installation in tight spaces, no tools needed. Versatile use for cars, motorboats, and multiple vehicle parts. Reliable brass pins ensure excellent electrical conductivity. Saves time and money with direct replacement.	No instructions included, might confuse first-time users. Limited color options, only comes in standard black. Not for heavy-duty industrial use, designed for cars only.

Perfect For:

This PACLVIO 4Pcs 5 Pin 12V 30A Car Starter Switch is perfect for car owners who need a reliable and easy-to-install replacement for their auto fuel pump relay. It’s great for DIY repairs and works well in tight spaces.

Ready to Purchase?

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8. Weasch 10 Pack Style 12AWG Relay Socket, 12V DC 5-PIN SPDT, Interlocking Relay Socket Harness Base with Wires

This 12V DC relay socket fits 5-pin SPDT relays. It has thick 12AWG wires for large currents. The interlocking base keeps wires in place.

Color-coded wires connect to pins 85, 30, 86, 87, and 87A. The pack has 10 sockets with wire harnesses.

Pros	Cons
Built-in safety with heavy-duty 12AWG wires Fits easily to your 5-pin SPDT relays Stay organized with interlocking cable layout No confusion with clear color-coded wiring Get your money’s worth with this 10-piece pack	No mounting hardware included, requires extra purchase. Limited wire length, may not fit all setups. No color-coded diagram, harder to install for beginners.

Perfect For:

DIY car enthusiasts and mechanics who work on car electronics will love this relay socket. It is perfect for setting up door locks, warning lights, and truck circuits.

Ready to Purchase?

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9. Relay 28300-10020, 12V 4 Pins Purple Starter Relay 28300-10020 156700-0503 – Compatible for Toyota Camry Corolla Lexus Various Models

The Relay 28300-10020 is a 12V 4-pin starter relay designed for Toyota, Lexus, Camry, and Corolla models. It ensures reliable starting power for your vehicle.

This relay features a secure 4-pin design for a precise connection. It works with 12V systems and fits various Toyota and Lexus models. Installation is quick and easy, with no complex steps.

It replaces multiple part numbers and meets OEM standards. The relay offers smooth ignition and long-lasting performance. A trusted choice for your vehicle’s starting system.

Pros	Cons
Steady 12V power helps your engine start smoothly. Four pins give a steady, secure connection. Fits many Toyota and Lexus models with ease. Matches common part numbers for a quick swap. Easy to install with no complex wiring.	Not universal: Only fits specific Toyota and Lexus models. No DIY kit: Requires basic tools for installation. Single function: Only works as a starter relay, no extra features.

Perfect For:

This starter relay is perfect for Toyota and Lexus drivers with Camry, Corolla, or similar vehicles. It is ideal for anyone needing a simple, reliable replacement.

Ready to Purchase?

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10. Nilight 50003R Automotive Set 5-Pin 30/40A 12V SPDT with Interlocking Relay Socket and Wiring Harness-5 Pack, 2 Years Warranty

The Nilight 50003R Automotive Set is a 5-pack of 5-pin 30/40A 12V SPDT relays with interlocking relay sockets and wiring harnesses. It comes with a 2-year warranty, ensuring reliable performance and peace of mind.

This set features high switching capability, handling 40A/14V DC normally open and 30A/14V DC normally closed. The premium quality relays and sockets are made with high-grade materials, ensuring durability and a long lifespan.

Easy to install, simple wiring, and neat appearance. Male-female slot design for secure connections. Color-coded wires for convenient setup.

Pros	Cons
40A power handles heavy vehicle loads. 30A contact gives steady daily performance. Color-coded wires make setup fast and clean. Easy-fit plug keeps relay wiring neat. Two-year warranty adds peace of mind.	No mounting hardware included, requires extra purchase for secure installation. Limited to 12V systems, not compatible with higher voltage setups. Warranty only 2 years, shorter than some competitors’ coverage.

Perfect For:

This set is perfect for DIY drivers, off-road fans, and auto experts who need a fast, clean way to wire LED light bars and other accessories.

Ready to Purchase?

View Price on Amazon (paid link)

Buying Guide

Automotive engine relays are key parts that keep your vehicle running smoothly. Choosing the right one saves time and money.

Here’s what to consider when buying:

Voltage and Amperage: Match the relay’s voltage (12V) and amperage (30A/40A) to your vehicle’s needs. Wrong specs can cause damage.
Pin Configuration: Check if it’s a 4-pin or 5-pin relay. The right pins ensure proper connections.
Waterproof Design: Look for waterproof relays if your vehicle faces harsh weather or water exposure.
Compatibility: Ensure the relay fits your car, truck, or boat. Some are universal, while others are model-specific.
Durability: Choose relays with heat-resistant and corrosion-proof materials for long-lasting use.
Ease of Installation: Pick relays with simple wiring and compact designs for hassle-free setup.
Warranty: A warranty adds peace of mind, ensuring quality and reliability.

With these factors in mind, you’ll find the perfect relay for your vehicle.