Mercury – Outer Helm Extension Harness | 20-Foot Extension | 84-8M0159752

Overview
This 20-foot extension gives the outer engines on triple- and quad-engine rigs the reach they need when the standard harness falls short. Wide transoms and long rigging runs can make things tight, and this harness keeps you from forcing sharp bends or stretching cables. It lets the wiring take a smoother path so everything feels calmer at the helm. It’s a simple add-on that makes big multi-engine layouts easier to rig and maintain.

Key Features
    • 20-Foot Extension – Adds plenty of length for wide beams and long routing paths.
    • Outer-Engine Use – Designed for the outer engines on triple or quad setups.
    • OEM Connectors – Factory plugs that lock in firmly.
    • Flexible Routing – Helps avoid pinched spots or tight corners.
    • Steady Signal Path – Keeps throttle and shift communication consistent.

Engine & Boat Compatibility
    • Triple engine
    • Quad engine
    • Outer-engine helm pathways

Performance & Practical Benefits
The extra length lets the wiring follow a natural route instead of being squeezed through tight areas. Controls tend to feel smoother because nothing is kinked or pulled too hard. It also gives you more room to work when you’re back there doing service—big boats get cramped fast, and this helps keep things open. Everything feels a bit more organized and predictable.

Why Buy OEM
OEM harnesses hold up well to heat, vibration, and saltwater spray. The connectors fit exactly the way Mercury intended, so you don’t end up dealing with loose plugs or strange electrical hiccups. It’s wiring built to last.

FAQ
Q1: How do I know if I need this extension?
A: If the outer engines on your triple or quad setup feel tight to route, this 20-footer usually fixes the reach issue.

Q2: Does it need any setup?
A: Nope—just plug it in.

Q3: Is it suitable for saltwater?
A: Yes. A quick rinse now and then keeps it in good shape.

Q4: Any install tips?
A: Give it a relaxed path with smooth bends so the harness isn’t under tension.

Q5: What are early signs of wear?
A: Jerky controls, intermittent signals, or rubbing spots on the jacket.