Littlefuse wire harness

The Littelfuse wire harnesses are especially designed and manufactured for overload and heat protection. It keeps trucks, cars, boats and machines running without any errors. The materials used in it are premium quality.

Littlefuse’s important for wire harness

The wire harness is the backbone of any electrical system. It keeps the wires all in one nice bundle so nothing gets tangled or broken. Every circuit is protected from damage by the power of Littelfuse products at the heart of this bundle. If there’s a power spike or a short, the fuse is the first thing to break the flow. That saves the wires, the battery, and the entire mechanism behind them. For more than 90 years, Littelfuse companies have been building that trust around the world. Engineers use these fuses because they always work the same way. Design, testing and quality checks are directed from Littelfuse’s headquarters in Chicago worldwide. All components are engineered for extreme heat, vibration and moisture. That’s why a littelfuse wire harness stands out in cars and boats and factories.

Little fuse blade types

Series: 287

Series: 287

ATOF ® Automotive Blade Fuse

Series: 297

Series: 297

MINI® 32V Fast-Acting Automotive Blade Fuse

Series: 327

Series: 327

MICRO2® 32V Blade Fuse

Series: 337

Series: 337

Micro3

Series: 891 LP MINI

Series: 891 LP MINI

Low-Profile MINI® 58V Blade Fuse

Series: 299

Series: 299

MAXI Blade Fuse

Series: MINI Smart Glow

Series: MINI Smart Glow

Aftermarket - 297 Series - MINI® Fast-Acting Automotive Blade Fuse Smart Glow

Series: ATO Smart Glow

Series: ATO Smart Glow

Aftermarket - 257 Series - ATO® Fast-Acting Automotive Blade Fuse Smart Glow

Little fuse substitube solution

Little fuse substitube solution

Mini size inline fuse holder

Little parts do a lot, even in small spaces. Mini Inline Fuse Holder The compact design is perfect for tight wiring runs. It holds a littelfuse mini fuse tight no loose wobble. Rain, dust and road grime can’t touch the fuse inside. This keeps the connection dry and the current flowing year-round. Ideal for motorcycles, ATVs and small accessory circuits. The compact shell is resistant to cracking in cold winter months. Replacing a blown fuse requires no tools and takes seconds. The wire leads are already stripped for quick connection. This littelfuse inline fuse holder shows that big protection comes in small parts.

Medium size fuse holder

Medium fuse holders are positioned in between the small and heavy-duty types. They manage moderate loads found in car audio, lighting and water pumps. The shell is made of tough plastic that shrugs off heat. Inside, the fuse blade is held by brass contacts with a firm, even pressure. This maintains low resistance throughout the joint and prevents sparking. A medium holder usually has a clear cover to view the fuse. You can see its status in seconds, no guessing around. Littelfuse relay harness setups in daily driver cars A lot of people buy this size. It is a reliable bridge between light accessories and full power circuits.

Large size fuse holder

Large fuse holders protect the largest loads in a vehicle or boat. Winches, inverters and thick battery cables require much strength. The housing is thick and water, oil and dirt proof. Bolt-style terminals keep the large-gauge wire from slipping over time. This design can fit high-amp fuses used in trucks and marine rigs. Low heat build up under continuous heavy current draw. A tight seal prevents corrosion of the metal contacts inside. This size is trusted for off-road rigs and commercial fleet vehicles. Works great as part of a complete littelfuse wire harness kit. Built tough. Built safe. Built for the toughest jobs on the road.

Little fuse for automotive fuse holders

Add-A-Circuit Mini Fuse Tap Wiring Harness

Add-A-Circuit Mini Fuse Tap Wiring Harness

A new accessory doesn't need to mean ripping out the entire car's wiring. With this fuse tap you can add power without messing with the wiring in the fuse box. Just plug it into an existing fuse in the panel. It draws clean power to power lights, cameras or a phone charger. A real littelfuse mini fuse is included in the design for reliable protection at all times. This easy install involves no cutting, splicing or soldering. Designed to fit the standard mini fuse slots found in most modern vehicles. This keeps the original circuit completely intact and fully protected. DIY fans love how fast and clean this upgrade is.

Waterproof Inline Automotive Fuse Holder Harness

Waterproof Inline Automotive Fuse Holder Harness

Water and electricity don’t mix well, especially in outdoor vehicles. Littelfuse wire harness solves that problem with a fully sealed rubber boot. Littelfuse waterproof fuse connections stay dry in heavy rain or mud. The seal also blocks dust, salt spray and grime from the engine bay. This makes it ideal for trucks, boats and off-road builds. Corrosion can’t seep in and weaken internal metal contacts. The harness uses marine-grade wire, which won’t crack in sunlight. Installers secure it via a simple twist-lock design. It withstands vibration, bumps and rough terrain. Trusted choice for all wiring work in any weather.

Multi-Circuit Fuse Block Assembly Harness

Multi-Circuit Fuse Block Assembly Harness

Some builds require power to many circuits at once. This assembly gives several fused outputs from one input wire. Each slot has its own fuse, so one blown fuse does not affect the rest. Works great for littelfuse pdm wiring setups in custom builds and race cars. Circuit tracing is fast and simple with block labels. The block is easy to mount with two or three screws. Heavy gauge input wire distributes even power to all outputs. This provides a low voltage drop, even when the circuit is fully loaded. Builders use this in campers, boats and off grid solar systems. One block, many circuits, full control of your power system.

Industrie e applicazioni

Automotive Repair Shops

Automotive Repair Shops

Mechanics rely on a reliable Littelfuse wire harness for their day-to-day repairs. Replacing the fuse quickly minimizes customer downtime. Clean wiring builds trust with every job performed. Littelfuse is why shops select consistent, proven results.

Marine and Boating

Marine and Boating

Salt water is hard on wiring and metal parts. A littelfuse waterproof fuse holder keeps boats running safely. Less dock-side repairs equals corrosion resistance. For trips out on the ocean, boaters rely on sealed harnesses.

Off-Road and Agriculture

Off-Road and Agriculture

Dust, mud and heavy vibration test every wire. Rugged Littelfuse wire harnesss protect tractors, ATVs and farm equipment. Rugged terminals, designed to endure harsh field conditions. Farmers need wiring that doesn’t fail in the middle of a season.

RV and Trailer Builds

RV and Trailer Builds

Campers need power for lights, fridges, pumps. A solid littelfuse fuse block handles many circuits at once. Safe nights on the road are a result of clean wiring. Simple, organized power systems are important to RV owners.

Solar and Renewable Energy

Solar and Renewable Energy

Solar needs a stable, protected power flow for installations. Fuse holders protect the battery from sudden surges. Sun and storm keep off-grid systems safe. Clean energy needs clean, safe wiring too.

Industrial and Telecom

Industrial and Telecom

Factories, telecom towers work day and night, 24/7. A reliable Littelfuse PDM wiring scheme handles multiple loads simultaneously. Reliability of fuses is paramount as downtime costs money. Proven, tested protection trusted by industrial teams every shift

One Harness, Multiple Voltage Classes

12V Platforms

12V Platforms

  • Most cars, trucks, and SUVs use 12V. Set fuse ratings toward the lower voltage. High ratings may harm sensitive regions. The right fuse stabilizes every 12V circuit.
  • There are many wire gauges for 12V systems. Over extended distances, thicker wire reduces harness resistance. Even with heavy load, voltage loss is small. Selecting the right gauge boosts performance.
  • Stereos and lights like 12V. Short, steady current bursts. Littelfuse microfuses can handle this load. Simple. Safe. Suitable for daily driving.
  • Driving stress tests a 12V harness. Vibration, heat, and cold affect performance. QL-Custom Technology Ltd. tests each harness similarly. Your 12V system will never fail.

24V Platforms

  • Heavy trucks, buses, and ships need 24V. A thinner cable absorbs more power from higher voltage. This higher current needs rated fuses. Matching components decrease heat and wire failure.
  • With less heat, the 24-volt fuse relay harness accommodates higher loads. Relays switch large current without damaging control wires. Protecting nearby switches and crucial electrical components "Relays prolong system life.
  • Commercial fleets need 24V everyday. Downtime on the job soon adds up. The appropriate Littelfuse wire harness keeps your truck operating and prevents electrical failure. Road breakdowns are reduced with reliable parts.
  • Some dual-voltage gear uses 12V and 24V. Well-designed harnesses isolate and protect these systems. Installation and repair wiring errors are reduced by clear markings. Controlling mixed systems requires engineering.
24V Platforms

Crimp Geometry and Contact Resistance

Crimp joint

A crimp joint is pure mechanical force. No solder or glue.

The right crimp shape folds metal tightly around each strand of wire.

Bad crimps leave air gaps that quickly increase electrical current resistance.

Higher resistance builds up more heat at the joint over time.

A circuit can fail due to too much heat melting the insulation.

A good crimp tool applies even pressure the length of the terminal.

This creates a gas-tight seal that prevents air and moisture from entering.

Tight, gas-tight couplings withstand corrosion better than twisted ones.

Pull-force tests make sure each crimp meets strength standards.

QL-Custom Technology Ltd tests each crimp before shipping it to you.

Good crimp geometry is the unsung hero of every safe Littelfuse wire harness.

Crimp seal

Grommet-Sealed and Crimp-Verified

Grommet Sealing

Grommet Sealing

  • All wire entry points are sealed with grommets to prevent water and dust ingress. A small rubber ring keeps moisture away from the metal. Cheap harnesses tend to skip this step to cut costs. QL-Custom Technology Ltd. is never caught without a noteworthy seal.
  • A close grommet also prevents wires from chafing against sharp metal edges. Over many months of use this rubbing can wear through the insulation. Sealed edges means fewer shorts and a much longer life for the harness. Big failures are often caused by small parts.
  • The weatherproofing is most critical in engine bays and outdoor mounts. Heat oil and rain attack all exposed wire ends. A sealed Littelfuse waterproof fuse link will pass all three. This is true protection, not just a marketing gimmick.

Crimp Verification

  • Each crimp is pulled and tested before leaving the factory. This step catches the weak joints before they ever get to you. Most cheap harnesses skip this simple but vital check. Verification separates good wiring from great.
  • Visual inspection ensures that the crimp shape is even and symmetrical at each joint. A bad crimp usually indicates a weak, unreliable connection. Joints pass Spec. Verified with trained eyes and tools. Without this careful final check, no shipping happens.
  • Sample testing is done in batch to ensure consistent quality on large Littelfuse wire harness orders. That’s especially true for fleets and big commercial buyers. Consistent quality means same performance, every time. You get the same good result every time.
Crimp Verification

Recensioni dei clienti

★★★★★

The fuse holders arrived fast and fit perfectly on my truck build. Clean crimps, no loose connections at all. Will order again for my next project.

James Whitfield
James Whitfield
★★★★★

I needed a waterproof Littelfuse wire harness for my boat wiring. This held up great through two months of heavy rain and salt spray.

Sakio Rin
Sakio Rin
★★★★★

Our shop orders these in bulk for customer repairs. Consistent quality every single time we order. Great support team as well.

Sofia Thompson
Sofia Thompson
★★★★★

The fuse tap harness let me add a dash cam without touching my main wiring. Super simple and worked on the first try.

Robert Miller
Robert Miller
★★★★★

Used the 24V relay harness for our fleet trucks. No failures after six months of daily heavy use. Impressed with the durability.

Stanley Kison
Stanley Kison
★★★★★

Great customer service when I had questions about fuse ratings. They helped me pick the right size fast. Order arrived quickly too.

Emeia Hemsworth
Emeia Hemsworth

Upgrade to Top- Grade Littelfuse wire harness

Wiring parts should never be a gamble to purchase. QL-Custom Technology Ltd. eliminates that risk with harness solutions that are tried, tested and sealed. All Littelfuse wire harnesses are strictly crimped and sealed checked before the shipment. We carry a complete line of holders, blocks and fuses from small Littelfuse mini fuses to large heavy duty fuse holders. Having trouble finding the right part? We study the Littelfuse wire harness manual so you don’t have to guess. We know Littelfuse semiconductor technology and how it protects your circuits from surges and heat. “We are trusted partners in the wiring world and we bring real engineering knowledge to every order. Whether you need one holder or a full fleet order, we deliver fast, accurate, and ready to install.