WM686 4-Pin Relay 12V 24V 100A–200A Car Starter Switch

WM686 High-Current Relay – 4-Pin Normally Open | 12V & 24V Compatible

Upgrade your vehicle's electrical system with the WM686 4-Pin Normally Open Relay. Designed for 12V and 24V DC systems, this heavy-duty relay handles up to 200A of continuous current, making it ideal for car starters, split-charge setups, battery isolators, and high-draw accessory switching. Whether you're wiring a second battery, protecting your starter circuit, or managing high-amperage loads, the WM686 delivers reliable, consistent switching performance.

Key Features

• Wide Voltage Compatibility: Works seamlessly with 12V and 24V DC electrical systems — perfect for cars, trucks, vans, RVs, and marine applications.
• High-Current Capacity: Available in 100A, 120A, and 200A ratings to match your specific circuit requirements.
• Durable Construction: Nylon shell paired with a brass inner core delivers excellent heat resistance and corrosion resistance for long-lasting performance in demanding environments.
• 4-Pin Normally Open Design: Clean, straightforward wiring — the circuit opens at rest and closes when energized, giving you precise control over high-amperage loads.
• Compact & Space-Saving: Low-profile form factor fits easily into tight engine bays or under-dash installations without crowding other components.
• Ready to Install: Works right out of the box — no complicated programming or additional hardware required.
• Available in 6 Color Options: Choose a color to help organize and identify your relay circuits at a glance.

Specifications

• Voltage: DC 12V / 24V
• Current Rating: 100A / 120A / 200A (select your option)
• Pin Configuration: 4-Pin
• Contact Type: Normally Open (NO)
• Material: Nylon Shell + Brass Inner Core
• Model: WM686

Common Applications

• Car, truck & SUV starter circuits
• Split-charge / dual-battery systems
• Battery isolators & battery management
• High-draw winch, lighting & accessory switching
• RV, marine & off-road electrical systems

For guidance on safe automotive electrical wiring and component installation, visit the U.S. Consumer Product Safety Commission (CPSC) for consumer safety resources.

Frequently Asked Questions

Q: What vehicles and systems is the WM686 4-Pin Relay compatible with?

A: The WM686 relay is compatible with any DC 12V or 24V electrical system, including cars, trucks, SUVs, vans, RVs, and marine vessels. Its broad voltage range makes it a versatile choice for both standard passenger vehicles and larger commercial or recreational setups.

Q: What does "normally open" mean for this relay?

A: A normally open (NO) relay means the circuit is open (disconnected) in its default resting state. When the relay coil is energized — typically by a small trigger signal — the internal contact closes, completing the high-current circuit. This design is ideal for starter circuits and accessory switching where you want the high-amperage load off by default.

Q: What materials make the WM686 relay durable enough for engine-bay use?

A: The WM686 features a nylon outer shell that resists heat and impact, combined with a brass inner core that provides excellent conductivity and resistance to corrosion. Together, these materials ensure the relay holds up reliably under the high temperatures and vibration typical of an engine-bay environment.

Q: Can I use this relay for a split-charge or dual-battery system?

A: Yes. The WM686's high current rating (up to 200A) and normally open configuration make it well-suited for split-charge and dual-battery installations. It can efficiently manage the charge flow between your primary and secondary batteries without voltage drop issues common to lower-rated relays.