Mercury – J-Box Y Harness | SmartCraft Network Splitter | 84-8M0165555

Overview

Some SmartCraft installations need an extra branch in the network to cleanly connect multiple devices without overloading a single port. The Mercury 84-8M0165555 J-Box Y Harness provides that split. It creates a tidy, reliable way to branch a SmartCraft connection so modules, gauges, or accessories can share the network without loose adapters or makeshift junctions. Once installed, it keeps the wiring simple and the communication steady.

Key Features

• Y-Style Network Split – Creates two clean SmartCraft branches from a single connection point.
• J-Box Integration – Designed for use with SmartCraft junction box layouts and harness runs.
• Stable CAN Communication – Maintains solid data flow between connected SmartCraft devices.
• OEM Connector Set – Uses factory SmartCraft ends for a secure, plug-in fit.
• Rigging Flexibility – Helps organize and expand network paths without clutter.
• Durable Marine Build – Withstands vibration, moisture, and long-term helm or bilge exposure.

Compatibility

• SmartCraft J-Boxes
• SmartCraft CAN networks
• SmartCraft modules, gauges, and accessories
• 10-pin SmartCraft harness connections

Performance & Practical Benefits

This harness gives you more freedom when laying out a SmartCraft network. Instead of stacking adapters or stretching a single connection, the Y-split keeps the network cleaner and easier to troubleshoot. The factory connectors hold tight through vibration, and the wiring maintains the network’s proper communication behavior. It’s a simple addition that keeps the system orderly and predictable.

Why Buy OEM

SmartCraft communication depends on correct pinout, shielding, and connector quality. Mercury’s OEM harness ensures the split behaves exactly the way the system expects, avoiding the glitches or intermittent issues that can happen with aftermarket jumpers. With the factory Y harness, the network remains stable and serviceable.

FAQ

Q1: When would I need a J-Box Y Harness?
Any time you need to branch a single SmartCraft port to support an extra gauge, module, or accessory.

Q2: Does using this harness affect network performance?
No. When used correctly, it maintains clean CAN communication across both branches.

Q3: Is installation complicated?
No. It’s a plug-in harness—just route it cleanly and connect each end.

Q4: Can this be used in saltwater boats?
Yes. The connectors and wiring are built for long-term marine exposure.

Q5: Does it replace the need for a full junction box?
Not in larger systems, but it’s ideal for small expansions where a full J-box isn’t necessary.