Truck-Lite 8-Outlet Electrical Distribution Module for Trailer Wiring

Organize and maintain your commercial trailer lighting system with this Truck-Lite 8-Outlet Electrical Junction Block, designed for compatible Truck-Lite plug-in trailer wiring harness systems.

Also known as an 8-outlet distribution module, this component provides a centralized connection point for multiple trailer lighting harnesses, helping simplify wiring repairs, harness replacement, and electrical troubleshooting.

Truck-Lite's 8-outlet distribution design accommodates compatible wiring connections for stop, turn, and tail lamps, marker and clearance lighting, license plate lights, and other trailer electrical circuits.

The keyed outlet arrangement helps connect compatible harness plugs in their intended orientation, while corrosion-preventative compound and retaining clips help protect connections during normal commercial trailer operation.

This distribution module is intended for compatible Truck-Lite 77 Series electrical harness systems.

Truck-Lite Reference: 77808 (verify against product identification)
Roll Off Truck & Trailer Parts SKU: LT188
Product Type: 8-Outlet Electrical Distribution Module
Number of Outlets: 8

Features & Benefits

• Eight Electrical Outlets: Provides eight connection points for compatible plug-in trailer wiring harnesses.

• Truck-Lite 77 Series Application: Designed for compatible modular trailer lighting and electrical harness systems.

• Centralized Wiring Distribution: Helps organize multiple trailer lighting connections in one location.

• Keyed Connector Outlets: Helps ensure proper orientation of compatible electrical plugs.

• Tin-Plated Brass Contacts: Manufacturer-documented contact construction for the 77808 module.

• Corrosion Protection: Truck-Lite specifies factory-applied NYK-77 corrosion-preventative compound.

• Stainless Steel Retaining Clips: Help secure compatible harness connections and reduce strain at the module.

• Serviceable Harness Connections: Plug-in design can simplify maintenance compared with replacing larger wiring harness sections.

• Commercial Trailer Applications: Used in compatible heavy-duty truck and trailer lighting systems.

Product Specifications

What Does an 8-Outlet Junction Block Do?

Commercial trailers use multiple electrical harnesses to distribute lighting signals throughout the vehicle.

The Truck-Lite 8-outlet distribution module provides a common connection point for compatible harness assemblies.

Instead of connecting each lighting harness through a separate field-wired junction, compatible Truck-Lite modular harnesses plug into the distribution module.

Depending on the trailer's electrical configuration, the module may distribute connections serving:

• Stop lamps

• Turn signal lamps

• Tail lamps

• Marker lamps

• Clearance lamps

• License plate lighting

• Additional trailer lighting harnesses

• Double-trailer electrical connections

Important: The available lighting functions depend on the installed wiring harnesses and trailer electrical system.

Designed for Truck-Lite 77 Series Wiring Systems

Truck-Lite's 77 Series harness system uses keyed connectors and modular wiring components designed to simplify installation and replacement.

The 8-outlet distribution module is one component of this system.

Manufacturer documentation identifies several construction features:

Keyed Electrical Outlets

Each outlet is designed for compatible connectors to help establish the correct connection orientation.

Tin-Plated Brass Contacts

Electrical contact surfaces are designed for reliable connections in supported wiring applications.

NYK-77 Corrosion Protection

The manufacturer specifies corrosion-preventative compound inside the module to help protect electrical connections from moisture-related deterioration.

Stainless Steel Retaining Clips

Retainers help secure connected harness plugs and reduce strain between the module and wiring assembly.

Common Truck and Trailer Applications

The Truck-Lite 8-outlet junction block is intended for compatible electrical harness installations on:

• Roll-off trailers

• Semi-trailers

• Dump trailers

• Flatbed trailers

• Equipment trailers

• Waste and recycling trailers

• Commercial hauling equipment

• Heavy-duty truck and trailer lighting systems

Compatibility is determined by the existing wiring harness and module connections, not the trailer type alone.

8-Outlet vs. 4-Outlet Distribution Modules

Truck-Lite also offers a 4-outlet distribution module, identified as part #77804.

8-Outlet Module — 77808

• Eight electrical harness connection outlets

• Used where the wiring configuration requires additional connections

• Intended for compatible Truck-Lite 77 Series harness systems

4-Outlet Module — 77804

• Four connection outlets

• Used in configurations requiring fewer electrical connections

These are different components. Verify the original module and harness requirements before ordering.

Why Replace a Damaged Trailer Junction Block?

Electrical distribution modules operate in environments exposed to road spray, dirt, salt, vibration, and repeated trailer movement.

Over time, electrical connectors or retaining components may become damaged or corroded.

Common reasons to inspect or replace a distribution module include:

• Broken or damaged connector outlets

• Corroded electrical terminals

• Loose or damaged harness connections

• Broken retaining clips

• Cracked or damaged housing

• Intermittent trailer lighting operation

• Wiring repairs requiring replacement of an existing module

A lighting problem can also be caused by a damaged harness, poor ground connection, failed lamp, or towing vehicle wiring issue.

Inspect the entire electrical circuit before concluding that the junction block needs replacement.

How to Verify the Correct Replacement

Before ordering, compare this distribution module with the component currently installed on your truck or trailer.

1. Check the Manufacturer Part Number

Look for Truck-Lite 77808 on the original module or in the equipment's parts documentation.

2. Count the Outlets

Verify that the original module has eight electrical outlets.

3. Compare Connector Shape

Make sure the original harness plugs match the keyed outlet configuration.

4. Check the Harness Series

Confirm that your trailer uses compatible Truck-Lite 77 Series wiring components.

5. Inspect the Mounting Arrangement

Compare the mounting location, overall module shape, and available installation clearance.

6. Inspect Related Harnesses

Check for damaged plugs, corroded terminals, missing retaining clips, or damaged wiring.

Important: This distribution module is not a universal replacement for every 8-terminal or 8-port trailer junction box.

Frequently Asked Questions

What is a Truck-Lite 8-outlet junction block?

It is an electrical distribution module that provides eight connection points for compatible trailer wiring harnesses.

What is Truck-Lite part number 77808?

Truck-Lite 77808 is an eight-outlet distribution module used in compatible trailer electrical harness systems.

Is this part of the Truck-Lite 77 Series?

Yes. The Truck-Lite 77808 distribution module is associated with the 77 Series harness system.

What trailer lights can connect through this module?

Depending on the harness configuration, compatible circuits may include stop, turn, tail, marker, clearance, and license plate lighting.

Does the module have corrosion protection?

Truck-Lite specifies NYK-77 corrosion-preventative compound for the 77808 distribution module.

Does it use standard screw terminals?

The 77808 is a keyed, plug-in distribution module. It should not be confused with a conventional junction box that uses exposed screw terminals.

What is the difference between Truck-Lite 77808 and 77804?

The 77808 has eight outlets, while the 77804 is a four-outlet module.

Does this include a complete wiring harness?

No. This product is the distribution module; the complete vehicle wiring harness and lighting components are separate.

Will this fit any commercial trailer?

Not necessarily. Verify that your trailer uses the correct Truck-Lite module, harness family, and mating connectors.

What is your store SKU?

The Roll Off Truck & Trailer Parts SKU is LT188.

Order Your Truck-Lite 8-Outlet Junction Block

Maintain your trailer's electrical system with replacement junction blocks, lighting harnesses, connectors, and other electrical components from Roll Off Truck & Trailer Parts.

This Truck-Lite 8-Outlet Electrical Distribution Module (SKU LT188) provides eight keyed harness connections for compatible commercial trailer lighting applications.

Order your Truck-Lite 8-outlet junction block online today!

Fitment Note: Verify manufacturer part number, outlet count, connector style, harness family, and mounting configuration before ordering. Complete wiring harnesses and lighting assemblies are sold separately.

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