• Truck-Lite 77851 Electrical Connector Kit – ½" ID, Series 77

  Repair or replace a damaged trailer wiring connection with the genuine Truck-Lite 77851 Electrical Connector Kit, designed for compatible Truck-Lite Series 77 commercial trailer wiring harness systems.

  Featuring a ½-inch inside diameter cable opening, this connector kit is intended for compatible 4- and 5-conductor round electrical cables.

  The Truck-Lite 77851 is identified as a connector boot kit within the manufacturer's Series 77 harness system, providing a replacement option for repairing compatible cable-end connections.

  Whether you're replacing a damaged electrical connector, repairing trailer lighting wiring, or maintaining a commercial trailer's electrical distribution system, this Truck-Lite connector kit offers a solution for compatible installations.

  Truck-Lite Part Number: 77851

  Roll Off Truck & Trailer Parts SKU: LT093

  Cable Opening: ½ Inch Inside Diameter

  Cable Application: 4- and 5-Conductor Round Cable

  Product Series: Truck-Lite 77 Series

  IMPORTANT: THIS IS A CABLE CONNECTOR KIT, NOT A COMPLETE SEVEN-POLE TRACTOR-TO-TRAILER PLUG OR RECEPTACLE.

  Features & Benefits

  • Genuine Truck-Lite Part #77851: Original Truck-Lite electrical connector kit for compatible trailer harness systems.

  • ½" Cable Opening: Designed for compatible round electrical cable requiring a matching cable-entry size.

  • 4- and 5-Conductor Cable Applications: Supplier-documented cable compatibility for Truck-Lite 77851.

  • Series 77 Harness System: Intended for compatible Truck-Lite modular trailer wiring applications.

  • Electrical Connector Repair: Replace a damaged or worn cable-end connection without necessarily replacing the entire wiring harness.

  • Commercial Trailer Applications: Suitable for compatible heavy-duty truck and trailer electrical systems.

  • Exact Part Identification: Truck-Lite part number 77851 helps customers identify the correct replacement.

  • Additional Cable Connector Sizes Available: Compare our ¾-inch and ⅜-inch electrical connectors to find the correct size.

  Product Specifications

  Specification	Details
  Manufacturer	Truck-Lite
  Manufacturer Part Number	77851
  Store SKU	LT093
  Product Type	Electrical Connector / Boot Kit
  Product Series	Truck-Lite Series 77
  Cable Opening / Inside Diameter	½ Inch
  Compatible Cable Type	4- and 5-Conductor Round Cable
  Primary Application	Commercial Trailer Wiring Harnesses
  UPC	735111042525
  Supplier-Listed Weight	2 oz
  Quantity	One Connector Kit
  Complete Trailer Cable	Not Included
  Complete Wiring Harness	Not Included
  Complete Seven-Pole Trailer Plug	Not Included
  Exact Internal Kit Components	Verify Against Supplied Package

  What Is the Truck-Lite 77851 Connector Used For?

  Commercial trailers use electrical wiring harnesses to distribute power and lighting signals between the main trailer cable, electrical distribution modules, and individual lighting components.

  Truck-Lite's Series 77 harness system uses compatible connector components to create and service these electrical connections.

  The Truck-Lite 77851 connector boot kit is used for compatible round-cable connections within this harness family.

  The ½-inch opening is an important identification measurement when matching the connector to an existing electrical cable.

  Typical service applications include:

  • Trailer lighting wiring repairs

  • Replacement of damaged cable-end connectors

  • Truck-Lite Series 77 harness maintenance

  • Commercial trailer electrical distribution connections

  • Roll-off trailer electrical repairs

  • Heavy-duty trailer wiring maintenance

  • Compatible 4- and 5-conductor cable connections

  Important: Compatibility depends on the cable, mating connector, and existing harness system. The ½-inch measurement alone does not guarantee fitment.

  Truck-Lite Series 77 Wiring System

  Truck-Lite's Series 77 electrical harness system includes connectors, distribution modules, and related wiring components used in commercial trailer applications.

  The 77851 kit is identified by suppliers specifically for compatible 4- and 5-conductor round cables.

  When selecting replacement electrical components, verify:

  • Cable outside diameter

  • Number of conductors

  • Original connector design

  • Compatible harness family

  • Mating connector arrangement

  • Required installation components

  This product should not be confused with a standard seven-pole trailer electrical plug.

  ½" vs. ¾" Trailer Electrical Connectors

  Different trailer cable sizes and conductor configurations require different connector kits.

  We also offer alternative electrical connector sizes.

  Connector	Store SKU	Cable Opening
  Truck-Lite 77851	LT093	½"
  ¾" Electrical Connector	LT092	¾"
  ⅜" Electrical Connector	LT094	⅜"

  The ¾-inch version is associated with Truck-Lite 77852 for compatible 6- and 7-conductor round cables.

  These connector sizes are not automatically interchangeable.

  Before ordering, compare the original connector and the cable's actual outside diameter.

  Why Replace a Damaged Trailer Electrical Connector?

  Commercial trailer wiring components operate in demanding conditions that can include moisture, dirt, vibration, road salt, and repeated movement.

  Over time, electrical connectors may become damaged, corroded, or worn.

  Common reasons for replacement include:

  • Cracked or broken connector components

  • Damaged cable-end connection

  • Loose electrical connection

  • Corroded terminals

  • Damaged cable entry

  • Intermittent trailer lighting

  • Worn or damaged harness connection

  • Electrical repairs involving replacement of the cable or harness

  Electrical problems may also originate elsewhere in the wiring system.

  Inspect the complete electrical connection before replacing the connector.

  How to Verify the Correct Replacement Connector

  1. Confirm the Manufacturer Part Number

  Check your existing component or equipment parts documentation for Truck-Lite 77851.

  2. Measure the Cable

  Verify your application requires a ½-inch cable opening and compare the cable's actual outside diameter.

  3. Check the Conductor Configuration

  Confirm that your wiring uses a compatible 4- or 5-conductor round cable.

  4. Identify the Wiring Harness System

  Verify that your existing system uses compatible Truck-Lite Series 77 components.

  5. Compare the Connector Arrangement

  Check the original connector's shape, cable entry, and mating connection.

  6. Confirm Installation Requirements

  Verify the required terminals, crimping or assembly procedures, and any additional components needed for the repair.

  Important: Matching the cable opening is not sufficient by itself. The connector design and electrical application must also match.

  Frequently Asked Questions

  What is Truck-Lite part number 77851?

  Truck-Lite 77851 is an electrical connector boot kit used with compatible Series 77 wiring harness applications.

  What size cable opening does it have?

  This connector is listed with a ½-inch inside diameter cable opening.

  What cable configurations does it support?

  Published supplier information identifies 77851 for compatible 4- and 5-conductor round cables.

  Is this a complete 7-way trailer plug?

  No. This is a Series 77 electrical connector kit, not a complete seven-pole tractor-to-trailer plug.

  Can I use this on seven-conductor round cable?

  Truck-Lite 77851 is identified for 4- and 5-conductor cable applications. Truck-Lite 77852 is a separate connector kit associated with compatible 6- and 7-conductor cables.

  Is this a genuine Truck-Lite product?

  Yes. This product is identified as Truck-Lite part number 77851.

  Does this include a complete wiring harness?

  No. The electrical cable and complete wiring harness are separate components.

  Will it fit any ½-inch cable?

  Not necessarily. Verify the cable diameter, conductor configuration, connector style, and mating connection.

  What is the UPC?

  The published UPC is 735111042525.

  What is the store SKU?

  The Roll Off Truck & Trailer Parts SKU is LT093.

  Order Your Truck-Lite 77851 Electrical Connector Kit

  Maintain your trailer's electrical wiring with genuine Truck-Lite connectors, wiring harnesses, distribution modules, and other replacement electrical components from Roll Off Truck & Trailer Parts.

  This Truck-Lite 77851 ½-inch Electrical Connector Kit (SKU LT093) is intended for compatible Series 77 trailer wiring applications using 4- and 5-conductor round cable.

  Order your Truck-Lite 77851 replacement electrical connector online today!

  ½" CABLE OPENING — SERIES 77 CONNECTOR KIT

  Fitment Note: Verify cable outside diameter, conductor configuration, original connector part number, and mating harness compatibility before ordering. This product is not a complete seven-pole trailer plug.

SKU: