Ronybuy 5-Pin Relay Kit for Automotive 12V - Pack of 5, Waterproof 40/30A Sealed Harness

Ronybuy’s 5-pin waterproof relay kit is a ready-to-install 12V SPDT relay and harness set (pack of 5) built for automotive and marine circuits that need a durable 40/30A switching solution.

This relay kit combines sealed sockets, tinned copper wiring, and a clear pin-color harness to simplify replacing or upgrading vehicle and equipment electrical circuits. Designed for use with standard 12V automotive relays, each pre-wired socket provides IP65-level protection against dust and splashes and supports both positive and negative trigger configurations. The kit’s mix of 12 AWG and 16 AWG conductors gives you heavier current capability on the load legs and lighter gauge control wires for compact routing.

How is this relay kit protected against moisture and dirt?

Each socket housing uses a durable insulation shell, sealed terminal caps and rubber grommets to block water and contaminants. That makes these sockets suitable for exposed engine bays, under-hood mounts, or marine spray-prone areas when installed correctly.

• IP65-rated shell and sealed terminal caps for splash resistance
• Rubber ring seals keep dust and moisture away from metal contacts
• Durable insulation material resists oil and grime commonly found in engine compartments

What wiring and current capacity does the kit provide?

The harness pairs heavier 12 AWG tinned copper on the main load terminals (pins 87, 30, 87a) with 16 AWG control wires for coil connections (pins 85, 86). The relay contacts are rated for up to 40A switching and 30A continuous load, suitable for many vehicle accessories when load and duty cycle remain within limits.

• Pin 87 (blue) and pin 30 (red) and pin 87a (yellow) are 12 AWG tinned copper
• Pin 85 (black) and pin 86 (white) are 16 AWG tinned copper
• Operates at 12VDC (safe up to 14V max) with 40A/30A switching capability

Which devices and vehicles are compatible with this relay harness?

This kit is engineered for common 5-pin automotive relays and supports switches, horns, cooling fans, starters, lights, and similar 12V accessories. It works with cars, trucks, boats, ATVs, and off-road equipment where a compact, sealed relay socket is needed.

• Suitable for horns, radiator and auxiliary fans, starters, lights, and wipers
• Fits standard 5-pin SPDT 12V relays used in automotive systems
• Ideal for retrofit, repair, or new wiring harness projects on vehicles and boats

How should I install and troubleshoot this relay harness safely?

Follow the included wiring diagram and take care when seating a relay into the socket to avoid bending pins. Use proper fusing at the supply side, route wires away from sharp edges and hot surfaces, and consider professional installation if you're not comfortable with vehicle electrical systems.

• Refer to wiring diagram for correct pin mapping and trigger polarity
• Use inline fuses sized for the accessory and load leg current
• Secure and protect wires from abrasion and heat during installation

Who is this for? Ronybuy’s 5-pin waterproof relay harness pack of five is aimed at DIY mechanics, fleet maintainers, marine hobbyists, and off-roaders who need dependable sealed relay sockets with heavy-duty tinned copper wiring for 12V accessories. If you’re replacing worn relay bases, building a custom wiring harness, or upgrading circuits to a more water-resistant solution, this kit offers a clear color-coded harness, robust conductor sizes on load paths, and sealed protection to help prolong relay and contact life when installed and fused properly.