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858740T4 Mercury Harness | Genuine Used Part

858740T4 Mercury Harness | Genuine Used Part

$240.00 AUD
$240.00 AUD
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🔧 Product Description

Genuine Mercury Harness Assembly - Part Number: 858740T4

A genuine Mercury harness assembly used as an adapter harness in Mercury to Yamaha-style rigging / electrical conversion applications. This harness links compatible Mercury engine or control-system connectors to the matching Yamaha-style connection layout where the 858740T4 harness is specified.

⚙️ Key Features

  • Genuine Mercury harness assembly
  • Correct Mercury part number 858740T4
  • Adapter harness for Mercury to Yamaha-style connection applications
  • OEM Mercury factory harness assembly
  • Fitment depends on plug type, engine rigging and control-system layout

🚤 Compatibility

Commonly used on

  • Mercury to Yamaha adapter harness installations

Typically suits

  • Engine / rigging applications:
  • Mercury engine installations requiring Yamaha-style adapter connection
  • Mercury 14-pin to Yamaha-style rigging conversion applications where 858740T4 is specified
  • Mercury remote-control or instrumentation conversion setups using 858740T4
  • Mercury / Yamaha shared rigging interface applications matched by plug layout
  • HP Range: rigging-dependent
  • Engine Type: Mercury outboard rigging harness system
  • System Type: Adapter harness assembly
  • Serial Note: Harness fitment is plug- and rigging-specific. Match by exact engine serial number, control type, connector count and pin layout.

🔌 Function

The harness adapts electrical control or instrumentation circuits between compatible Mercury and Yamaha-style plug systems.

⚠️ Common Signs of Failure

  • No communication between control harness and engine
  • Intermittent gauge or warning function
  • Trim, start or key-switch circuit not operating
  • Corroded or damaged pins
  • Broken wire continuity inside harness
  • Fault changes when harness is moved
  • Incorrect adapter harness fitted to rigging system

🔄 Supersession & Cross Reference

OEM Supersession Chain

  • 858740T4 current / listed Mercury harness assembly reference

OEM / Related Numbers

  • 858740T4
  • 84-858740T4
  • 858740
  • Mercury to Yamaha adapter harness reference
  • Related rigging harness family reference

Aftermarket / Verified Equivalents

  • No aftermarket equivalent

📦 Condition

  • Genuine used part
  • Removed from running engine where applicable
  • In good working condition unless otherwise stated

Shipping & Delivery

Flat-rate shipping Australia-wide — $14.99 per order, no matter how many parts you add. Orders dispatch from our Kadina, South Australia store. Need it urgently or want to collect in person? Call us on 0412 532 984 before ordering.

Returns & Warranty

14-day change-of-mind returns — if it's not right or you ordered the wrong part, send it back within 14 days in the condition you received it for a refund or exchange. Full details in our Refunds & Returns policy.

Not sure this fits?

Ask us before you buy — we check part numbers and fitment every day. Call 0412 532 984 (Mon–Fri 8.30am–4.30pm) or message us through the contact page with your engine or vehicle details.

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