Mercury – MP Alert Harness Extension | 30-Foot Forward Routing Cable | 84-8M0054186

Overview

On larger boats—or layouts with long rigging runs—you may need extra length to bring an MP Alert light forward where swimmers, riders, or guests can see it sooner. The Mercury 84-8M0054186 MP Alert Harness Extension gives you 30 feet of reach so an MP Alert light can be mounted well ahead of the transom. It plugs directly into the MP Alert wiring, extending the system’s visibility and ensuring the Moving Prop warning is clear from multiple angles around the vessel.

Key Features

• 30-Foot Extension – Longest forward-routing harness option for MP Alert installations.
• Plug-In OEM Fit – Uses SmartCraft-grade connectors for simple, reliable installation.
• Increased Safety Visibility – Helps place MP Alert lights farther forward so swimmers can see warnings earlier.
• Flexible Routing Path – Extra length makes it easier to pass through hull cavities, bulkheads, and long console runs.
• Marine-Durable Build – Sealed cable and connectors designed for long-term exposure to moisture, spray, and vibration.

Compatibility

• All Mercury MP Alert systems using oval smart lights
• SmartCraft-compatible engines
• MP Alert Add-A-Light and Y-harness expansion setups
• Boats requiring extended bow or forward-deck light placement

Performance & Practical Benefits

When you add a forward-mounted MP Alert light, the safety zone around your boat expands dramatically. This 30-foot harness gives you the freedom to route the wiring cleanly and securely through long rigging channels, making installation easier on pontoon boats, large center consoles, saltwater fishing rigs, and cruisers. Once connected, the light activates automatically with the rest of the MP Alert system, flashing whenever the prop is spinning so anyone near the bow gets a clear warning.

Why Buy OEM

Mercury’s MP Alert system relies on exact connector fit, clean signal transfer, and robust water sealing. This OEM harness maintains that reliability, ensuring the forward light illuminates at the right time with full brightness. Aftermarket extensions often allow moisture intrusion or cause intermittent operation—but the factory harness is built specifically for Mercury’s requirements and harsh marine environments.

FAQ

Q1: When should I use the 30-foot extension?
When the distance from the MP Alert module to the intended light location exceeds 20 feet—common on large consoles, pontoons, or forward-deck installations.

Q2: Does this change how the MP Alert system operates?
No. It simply extends the wiring. The lights still activate automatically when the prop moves.

Q3: Is it compatible with all MP Alert oval lights?
Yes—any Mercury oval MP Alert light, including cowl-mounted and add-on lights.

Q4: Can this be used with a Y-harness?
Absolutely. It works alongside expansion components when adding extra lights.

Q5: Is installation difficult?
No. Plug in, route the harness, secure it, and the system is ready to go.