# 855212A1 Mercury Harness Adapter | Genuine Used Part

🔧 Product Description

  

Genuine Mercury Harness Adapter - Part Number: 855212A1

  

A genuine Mercury harness adapter used in selected Mercury and Mariner two-stroke carbureted outboard cylinder block / crankcase harness assemblies. This adapter is commonly listed as 84-855212A1 and is used in oil-injection and adaptor harness positions on supported 3-cylinder and 4-cylinder engines.

  

⚙️ Key Features

  

• Genuine Mercury harness adapter

• Correct Mercury part number 855212A1

• Also listed as 84-855212A1

• Used on selected Mercury / Mariner 3-cylinder and 4-cylinder two-stroke carbureted outboards

• Must be matched by exact serial-numbered parts diagram and harness connector layout

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 855212A1 current Mercury harness adapter reference

  

OEM / Related Numbers:

  

• 855212A1

• 84-855212A1

• 855212-A1

• 855212

• Harness adapter

• Harness assembly adapter

• Oil injection harness adapter

• UPC: 745061434868

  

Aftermarket / Verified Equivalents:

  

• No aftermarket equivalent

  

🚤 Compatibility

  

Commonly used on:

  

• Mercury / Mariner two-stroke carbureted outboard harness assemblies

• 3-cylinder 65 Jet / 75HP / 90HP oil-injection harness adaptor positions

• 4-cylinder 80 Jet / 100HP / 115HP / 125HP harness adaptor positions

  

Typically suits:

  

• Mercury 65 Jet - serial 0D283222 to 0G760299

• Mercury 65 Jet - serial 0G760300 to 0T979999

• Mercury 65 Jet - serial 0P017000 to 0P325499

• Mercury 65 Jet - serial 9793577 to 0P016999

• Mercury 65 Jet 3-cylinder - serial 0T980000 to 0T999999

• Mercury 65 Jet 3-cylinder - serial 1B000001 and up

• Mercury 75HP 3-cylinder - serial 0D283222 to 0G760299

• Mercury 75HP 3-cylinder - serial 0G760300 to 0T979999

• Mercury 75HP 3-cylinder - serial 0P017000 to 0P325499

• Mercury 75HP 3-cylinder - serial 0P325500 and up

• Mercury 75HP 3-cylinder - serial 0T980000 to 0T999999

• Mercury 75HP 3-cylinder - serial 1B000000 and up

• Mercury 75HP 3-cylinder - serial 1B000001 and up

• Mercury 75HP 3-cylinder - serial 9793577 to 0P016999

• Mercury 80 Jet - serial 0D283222 to 0G760299

• Mercury 80 Jet - serial 0G760300 to 0T979999

• Mercury 80 Jet - serial 0P017000 to 0P325499

• Mercury 80 Jet - serial 9793577 to 0P016999

• Mercury 80 Jet - serial 0T980000 to 0T999999

• Mercury 80 Jet - serial 1B000001 and up

• Mercury 90HP 3-cylinder - serial 0D283222 to 0G760299

• Mercury 90HP 3-cylinder - serial 0G760300 to 0T979999

• Mercury 90HP 3-cylinder - serial 0P017000 to 0P325499

• Mercury 90HP 3-cylinder - serial 0P325500 and up

• Mercury 90HP 3-cylinder - serial 0T980000 to 0T999999

• Mercury 90HP 3-cylinder - serial 1B000001 and up

• Mercury 90HP 3-cylinder - serial 9793577 to 0P016999

• Mercury 100HP 4-cylinder - serial 0D283222 to 0G760299

• Mercury 100HP 4-cylinder - serial 0G760300 to 0G965520

• Mercury 100HP 4-cylinder - serial 0P017000 to 0P058999

• Mercury 100HP 4-cylinder - serial 9793577 to 0P016999

• Mercury 115HP 4-cylinder - serial 0D283222 to 0G760299

• Mercury 115HP 4-cylinder - serial 0G760300 to 0T979999

• Mercury 115HP 4-cylinder - serial 0P017000 to 0P325499

• Mercury 115HP 4-cylinder - serial 9793577 to 0P016999

• Mercury 115HP 4-cylinder - serial 0P325500 and up

• Mercury 115HP 4-cylinder - serial 0T980000 to 0T999999

• Mercury 115HP 4-cylinder - serial 1B000001 and up

• Mercury 125HP 4-cylinder - serial 0D283222 to 0G760299

• Mercury 125HP 4-cylinder - serial 0G760300 to 0T979999

• Mercury 125HP 4-cylinder - serial 0P017000 to 0P325499

• Mercury 125HP 4-cylinder - serial 9793577 to 0P016999

• Mercury 125HP 4-cylinder - serial 0P325500 and up

• Mercury 125HP 4-cylinder - serial 0T980000 to 0T999999

• Mercury 125HP 4-cylinder - serial 1B000001 and up

• HP Range: 65 Jet / 75HP / 80 Jet / 90HP / 100HP / 115HP / 125HP

• Engine Type: Mercury / Mariner two-stroke carbureted 3-cylinder and 4-cylinder outboard

• Year Range: Serial-number controlled

• Serial Note: Confirm the engine serial number, oil-injection configuration and harness plug layout before installation.

  

🔌 Function

  

The harness adapter connects the specified engine wiring circuit into the cylinder block / crankcase harness assembly, allowing the correct oil-injection or adaptor harness connection on supported Mercury and Mariner outboards.

  

Common signs of failure:

  

• Damaged or broken harness connector

• Corroded terminals

• Oil-injection warning or related harness fault

• Intermittent electrical connection

• Harness plug does not lock securely

• Broken wire at adapter body

• Electrical fault changes when the harness is moved

  

📦 Condition

  

• Genuine used part

• Removed from running engine where applicable

• In good working condition unless otherwise stated

## Details

- **Price:** 2.5 AUD
- **Vendor:** Sawley's Auto and Marine
- **Tags:** Sawley’s AAM Used Parts – Electronic Components | ECU CDI & Electrical Parts

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 2.50 AUD | In stock |

## Images

- 855212A1 Mercury Harness Adapter | Genuine Used Part
- 855212A1 Mercury Harness Adapter | Genuine Used Part
- 855212A1 Mercury Harness Adapter | Genuine Used Part
- 855212A1 Mercury Harness Adapter | Genuine Used Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/855212a1-mercury-harness-adapter-genuine-used-part)
> Updated: 2026-06-29