Starter Solenoid Relay – Fits Mercury 8HP 9.9HP 15HP 30HP 40HP 50HP 60HP 75HP 90HP 4-Stroke (Replaces 89-825096T, 825096T01, 825096T, 18-5821)

Product Details

This Starter Solenoid Relay is an aftermarket replacement designed for Mercury 4-stroke outboard engines ranging from 8HP to 115HP, covering model years 1998 through 2010. Engineered to deliver reliable starting performance, this 12V relay is a direct-fit solution for a wide range of Mercury outboard configurations including E, EH, EL, ELH, ELPT, ELPTO, M, MH, ML, and MLH series motors.

This relay replaces OEM part numbers 89-825096T, 825096T01, 825096T, and Sierra 18-5821, ensuring seamless compatibility across multiple Mercury platforms.

• Direct replacement installation with factory-spec mounting
• 12V operating voltage for standard marine electrical systems
• Compatible with Mercury 4-stroke outboards from 8HP to 115HP

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

Voltage

12V

Type

Starter Relay Solenoid

Installation

Direct Replacement

Application

Mercury 4-Stroke Outboard Engines

What's in the Box

• 1 × Starter Solenoid Relay

Installation Notes

1. Disconnect the negative battery cable to prevent accidental electrical shorts.
2. Locate the existing starter solenoid relay on your Mercury outboard.
3. Disconnect all wiring terminals from the old relay, noting their positions for correct reassembly.
4. Remove the mounting hardware securing the old relay to the engine.
5. Position the new relay in the same mounting location and secure with original or equivalent fasteners.
6. Reconnect all electrical terminals in their original configuration, ensuring clean and tight connections.
7. Reconnect the negative battery cable and test starter operation to verify proper function.

Troubleshooting & FAQ

How do I know if my starter solenoid relay is failing?

Common symptoms include a clicking sound when turning the key with no engine cranking, intermittent starting issues, or complete failure to engage the starter motor. If the solenoid is overheating or showing visible corrosion, replacement is recommended.

Is this compatible with 2-stroke Mercury engines?

No, this relay is specifically designed for Mercury 4-stroke outboards from 1998 to 2010. Verify your engine stroke type and model year before ordering.

Will this work if my original part number is slightly different?

This relay replaces 89-825096T, 825096T01, 825096T, and Sierra 18-5821. If your OEM number matches any of these, fitment is confirmed. For other part numbers, cross-reference with Mercury documentation or contact support.

Can I install this myself or do I need a mechanic?

Installation is straightforward for users with basic electrical and mechanical skills. However, professional installation is recommended to ensure correct wiring and to avoid electrical system damage.

What causes starter relay failure on outboards?

Marine environments expose relays to moisture, salt, and vibration. Over time, contacts can corrode or wear, leading to poor conductivity or intermittent operation. Regular inspection and timely replacement help prevent starting failures.

How does this compare to the OEM Mercury relay?

This is an aftermarket replacement built to meet or exceed OEM specifications. It uses comparable materials and undergoes batch inspection to ensure consistent quality and reliable performance.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

• Verify images/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
• Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.