87-17009A5 Ignition Key Switch for Mercury | JLM Marine

Ignition Key Switch for Mercury Outboard – 87-17009A5

This ignition key switch is engineered for Mercury outboard remote control systems, providing reliable 3-position operation (Off-Run-Start) with push-to-choke functionality in the start position. Designed for Commander 2000 and 4000 series side-mount remote controls, it fits a wide range of 2-cylinder Mercury and Mariner outboards from 9.9HP to 30HP across model years 1986 through 2010.

Direct Replacement: OEM part number 87-17009A5 (Mercury 17009A5 SWITCH ASSY). Compatible with Commander 2000 (16900 Series) and Remote Control-4000 Side Mount systems without power trim.

• Magneto-style ignition switch with heavy-duty potted construction for marine durability
• Push-to-choke function in start position for easier cold starts
• Compact dimensions: 58.18 × 37.62 × 17.54 mm

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 × Ignition Key Switch

Installation Guide

1. Disconnect the battery before beginning any electrical work to prevent accidental shorts or sparks.
2. Access the back of your remote control box by removing the cover or housing screws. Locate the existing ignition switch.
3. Disconnect the wiring harness from the old switch, noting the wire positions or taking a photo for reference.
4. Remove the retaining nut or mounting hardware securing the old switch to the control panel.
5. Pull the old switch out from the front of the control panel.
6. Insert the new ignition switch into the panel opening from the front. Ensure proper orientation (Off-Run-Start positions match your control layout).
7. Secure the switch from behind with the retaining nut or mounting hardware. Tighten until snug but do not over-torque plastic threads.
8. Reconnect the wiring harness to the terminals on the new switch, matching your reference notes or photo.
9. Verify all connections are firm and properly seated. Check that no wires are pinched or exposed.
10. Reinstall the remote control cover or housing and secure all screws.
11. Reconnect the battery and test the switch in all three positions: Off, Run, and Start with choke function.
12. Confirm the engine starts normally and that the key can be removed only in the Off position.

Troubleshooting & FAQ

How do I confirm this ignition switch fits my Mercury remote control?
Check the compatible engine models table above for your HP rating, serial number range, and remote control series (Commander 2000 or 4000 Side Mount). You can also cross-reference your existing switch with OEM part number 87-17009A5 or verify fitment using the Mercury parts diagrams linked in the compatibility section.

What should I do if the engine won't start after installing the new switch?
First, verify all wiring connections match your original configuration and are fully seated. Check that the battery is reconnected and charged, and confirm the switch clicks firmly into each position (Off-Run-Start). If the issue persists, test for continuity across switch terminals in the Run and Start positions using a multimeter.

Can I use this switch on a remote control with power trim?
This switch is designed for non-power-trim Commander 2000 and 4000 side-mount remote controls. If your system includes power trim functionality, verify your control box wiring and switch terminal configuration match before installation.

How does the push-to-choke feature work in the start position?
When you turn the key to Start, you can push the key inward to engage the choke circuit, enriching the fuel mixture for easier cold starts. Release the push after the engine fires and return the key to the Run position.

What are signs that my ignition switch needs replacement?
Common symptoms include intermittent starting, the engine cutting out in the Run position, difficulty turning the key, inability to remove the key in Off position, or visible corrosion and damage to the switch housing or terminals.

OEM vs. Aftermarket—what's the difference?
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.