Starter Solenoid Relay – Fits Mercury/Mariner Outboard 115-250 HP (Replaces 89-817109A1, 89-817109A2, 89-817109A3)

Starter Solenoid Relay – Fits Mercury/Mariner Outboard 115-250 HP

This starter solenoid relay fits a wide range of Mercury and Mariner outboard engines, including models from 40 HP to 250 HP, primarily from the 1990s and 2000s. It serves as a reliable replacement for various 115, 125, 135, 150, 175, 200, 225, and 250 HP engine configurations.

This unit directly replaces Mercury part numbers 89-817109A1, 89-817109A2, and 89-817109A3. It also cross-references with common aftermarket parts, including Sierra 18-5834, Arco SW109, Arrowhead SMR6010, J&N 240-22131, and WAI 67-731.

• Installation: Designed for direct, hassle-free replacement.
• Connection: Standard 4-Terminal configuration with an isolated base.
• Electrical: Engineered for 12V DC systems.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Starter Solenoid Relay (Replaces 89-817109A3)

Installation Guide

1. Safety First: Before starting, disconnect the battery cables (negative terminal first) to prevent electrical shorts.
2. Locate the Old Solenoid: Find the existing starter solenoid, which is typically mounted on or near the starter motor assembly.
3. Label Wires: To avoid errors, label each wire with its corresponding terminal before disconnecting them. Taking a quick photo for reference is also a good idea.
4. Disconnect Terminals: Carefully remove the nuts and washers to disconnect the large battery/motor cables and smaller switch/ground wires.
5. Remove the Solenoid: Unbolt the old solenoid from its mounting point and remove it from the engine.
6. Mount the New Solenoid: Position the new solenoid and secure it using the original mounting hardware.
7. Reconnect Wires: Attach the wires to the correct terminals on the new solenoid according to your labels. Ensure all connections are tight.
8. Reconnect Battery: Reconnect the battery cables, starting with the positive terminal, then the negative terminal.
9. Test Operation: Turn the ignition key to the start position and listen for a distinct click from the solenoid, followed by the starter motor engaging the engine.

Troubleshooting & FAQ

How do I confirm this fits my engine?

This solenoid is designed for a broad range of Mercury/Mariner outboards from 40 to 250 HP. The most reliable way to ensure fitment is to match the part number from your old solenoid to one of the numbers listed in our cross-reference table (e.g., 89-817109A1, 89-817109A2, 89-817109A3, or an aftermarket equivalent like Sierra 18-5834).

What are the signs of a failing starter solenoid?

Common symptoms include a single loud click when you turn the ignition key but the engine doesn't crank, intermittent starting issues where it works sometimes but not others, or a starter that continues to run even after the key is released.

What is an isolated base solenoid?

This is a 4-terminal solenoid with an isolated base, meaning the case is not used for grounding. It requires a dedicated ground wire connected to the fourth terminal (one of the small posts) for the circuit to be complete. This design prevents grounding issues through the mounting bracket.

OEM vs. Aftermarket?

This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?

We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?

This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.