Sierra Marine Internal Engine Wiring Harness 18-99594 - Replaces OEM 583035 for Johnson Evinrude Sea Drive 2.6L 150-175 Hp

The Sierra 18-99594 is an internal engine wiring harness built for Johnson Evinrude outboards, using a round plug connector design to route electrical signals between the engine's internal components. It is engineered as a direct replacement for the original equipment harness on the Sea Drive 2.6L 6 cylinder powerhead, restoring proper electrical continuity where a factory harness has become brittle, corroded, or damaged from heat and vibration over time. The harness uses copper conductors for reliable current and signal transfer, matching the electrical performance expected of the original wiring.

This harness is intended for outboard owners and marine technicians performing an engine rebuild, electrical troubleshooting, or a preventive wiring replacement on applicable Johnson Evinrude powerheads. Because internal engine harnesses are routed through tight compartments and connect directly to ignition and sensor components, correct fitment to the engine's displacement, cylinder count, and horsepower rating is essential before installation.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99594
• OEM Cross Reference: 583035
• Material: Copper
• Weight: 0.9 pounds
• UPC: 808282398620
• Compatible Engine: Johnson Evinrude Sea Drive 2.6L 6 Cylinder
• Compatible Horsepower: 150 Hp, 155 Hp, 175 Hp
• Compatible Years: 1986-1987

Fitment

• Johnson Evinrude Sea Drive 2.6L, 6 Cylinder
• 150 Hp, 155 Hp, and 175 Hp engines, 1986-1987

Replaces (OEM)

• 583035

Frequently Asked Questions

What engines does the Sierra 18-99594 harness fit? The Sierra 18-99594 internal engine wiring harness fits Johnson Evinrude Sea Drive 2.6L, 6 cylinder engines rated at 150 Hp, 155 Hp, and 175 Hp for the 1986-1987 model years.

Is the 18-99594 harness a direct OEM replacement? Yes, the Sierra 18-99594 is designed to replace OEM number 583035 on applicable Johnson Evinrude engines, restoring the original electrical connections without modification.

What is the connector style used on this harness? This harness uses a round plug internal engine connector, matching the original Johnson Evinrude connector configuration on the Sea Drive 2.6L 6 cylinder powerhead.

What material are the conductors made of in the 18-99594 harness? The Sierra 18-99594 harness uses copper conductors for reliable electrical signal and current transfer between engine components.

How much does the Sierra 18-99594 harness weigh? The Sierra 18-99594 internal engine harness weighs 0.9 pounds.

What OEM part number does 18-99594 cross-reference to? Sierra part 18-99594 replaces OEM number 583035 on Johnson Evinrude Sea Drive 2.6L 6 cylinder engines.

Will this harness work on other horsepower Johnson Evinrude models outside 150-175 Hp? The Sierra 18-99594 is specified for 150 Hp, 155 Hp, and 175 Hp Johnson Evinrude Sea Drive 2.6L 6 cylinder engines from 1986-1987; fitment outside this range is not confirmed.

Is this harness suitable for an engine rebuild? Yes, the 18-99594 internal engine harness is commonly installed during an engine rebuild or wiring restoration on applicable Johnson Evinrude powerheads.

Does the 18-99594 harness include the full internal engine wiring or just a section? The Sierra 18-99594 is the complete internal engine harness with round plug connector for the Johnson Evinrude Sea Drive 2.6L 6 cylinder engine.

What UPC identifies the Sierra 18-99594 harness? The Sierra 18-99594 internal engine harness is identified by UPC 808282398620.