Waterproof 12V 40A 5-Pin Automotive Relay with Harness Socket

Keep your vehicle's electrical system running reliably with this Waterproof 12V 5-Pin 40A Automotive Relay. Engineered for cars, trucks, and other 12V vehicles, this relay features premium materials and a sealed, waterproof design — ideal for underhood and exposed mounting locations where moisture resistance is critical.

Premium Materials & Construction

Red Copper Coil — ensures excellent conductivity and long-lasting coil performance
Cu-Ag-Cr Alloy Contact Points — high-grade alloy touch points for reliable switching and reduced arcing
Red Copper Over-Current Protection — built-in safeguard against electrical overloads
Integrated Fuse — adds an extra layer of circuit protection for safer, more convenient installation
Waterproof Sealed Housing — protects internal components from moisture, dust, and road debris

Specifications

Voltage: 12V DC
Amperage: 40A
Pin Configuration: 5-Pin
Weight: 0.078 kg
Includes: 1 x Relay with Harness Socket

What's in the Box

1 × 12V 40A 5-Pin Waterproof Relay
1 × Matching Harness Socket

Why Choose This Relay?

Whether you're upgrading your vehicle's wiring, replacing a faulty relay, or building a custom automotive electrical harness, this relay delivers the current capacity and durability you need. The included harness socket makes wiring fast and clean, eliminating the need for additional connectors.

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Frequently Asked Questions

Q: What vehicle types is this 12V 40A 5-Pin automotive relay compatible with?

A: This relay is compatible with most 12V vehicles including cars, trucks, SUVs, and motorcycles. As long as your vehicle operates on a standard 12V DC electrical system and requires a 5-pin relay rated at 40A or below, this relay is a suitable fit for a wide range of automotive wiring applications.

Q: Why does this automotive relay have 5 pins instead of the standard 4?

A: A 5-pin relay includes an additional normally-closed (NC) terminal compared to a standard 4-pin relay. This allows the relay to switch between two circuits — useful in applications where you need one device to turn on while another turns off, offering greater wiring flexibility for advanced automotive setups.

Q: Is the harness socket included, and how does it simplify installation?

A: Yes, a matching harness socket is included with every relay. The socket provides dedicated connection points for each pin, allowing for clean, secure wiring without the need for soldering or extra connectors — making installation straightforward for both DIY enthusiasts and professional auto electricians.

Q: What makes this relay suitable for outdoor or underhood use?

A: The relay features a fully sealed, waterproof housing that guards the internal coil and contact points against moisture, condensation, and dust. Combined with its red copper over-current protection and Cu-Ag-Cr alloy contact points, it is built to perform reliably even in demanding underhood environments.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.