ONLINE LED STORE True Mods H6054 H4 LED Headlight Wiring Harness – Negative-to-Positive Conversion, Fused Relay Kit

The True Mods H6054 H4 LED Headlight Wiring Harness from ONLINE LED STORE converts negative-switched headlight systems into a reliable positive-switched relay setup for easy LED or sealed-beam upgrades.

Switching factory headlights to modern LED bulbs often fails on older vehicles with negative-switched headlight circuits. This Universal H4 (9003 / H6024 / H6054-compatible) relay harness is engineered to bridge that gap: it performs the negative-to-positive conversion, preserves your stock connectors, and delivers fused, relay-driven power to high and low beams so LEDs behave correctly and reliably.

How does this harness make an LED conversion simpler?

The kit wires relays to change two ground-switched signals into two positive-switched outputs while keeping a constant ground, eliminating flicker, dimming, and erratic behavior. Installation avoids cutting factory wiring—most installs are plug-and-play using the included sockets and harness.

• Converts negative switched (2 toggled grounds + 1 constant hot) to positive switched (2 toggled hots + 1 constant ground)
• Fused power feed protects LEDs and vehicle wiring
• Uses OEM-style H4/9003 sealed ceramic sockets for secure bulb contact
• Plug-and-play design preserves original harness for reversible installs

What vehicles and headlamp types will this relay harness work with?

This universal harness supports common H4/9003 and sealed-beam socket standards found on many older Toyotas, Subarus, Jeeps, Mitsubishis and other vehicles. It’s compatible with 7x6 (5x7), 4x6 (6x4), and other sealed-beam formats when those lamps use H4-style sockets.

• Fits H4/9003 and H6024/H6054-style connectors used in sealed-beam and modern retrofit bulbs
• Commonly used on Jeep CJ7, Cherokee XJ, Wrangler JK, Toyota Tacoma, older Subaru and Mitsubishi models
• Works with LED and halogen replacements that require stable positive switching
• Universal fit—can be adapted to many classic and off-road headlamp setups

What features ensure long-term reliability and safe operation?

True Mods designed this kit with durable components to handle higher current and heat from modern bulbs. The harness includes two relays, a fused main feed, ceramic headlight sockets resistant to heat, and a polycarbonate loom to protect wiring against abrasion and engine-bay temperatures.

• Dual relays provide dedicated power routing for high and low beams
• Inline fuse offers overcurrent protection for the upgraded lighting system
• Ceramic sockets resist heat cycling and ensure secure bulb contact
• Heat-resistant polycarbonate loom prevents chafing and melt damage

How difficult is installation, and will I need to alter factory wiring?

Installation is designed to be straightforward and reversible: most users splice only the accessory power or attach the battery feed, while the headlight plugs connect directly to the harness sockets. No permanent cuts to the vehicle’s original headlight harness are required, making this suitable for DIY installs or professional shops.

• Plug-in headlight sockets replace factory connectors without cutting stock wiring
• Battery/constant power attaches to fused lead; relays activate from existing switch signals
• Typical installation time: minutes to an hour depending on vehicle access
• Comes with a 1-year manufacturer warranty for peace of mind

Who is this for: This True Mods H6054 H4 relay harness is made for vehicle owners upgrading to LED or aftermarket sealed-beam headlights on negative-switched systems—whether you’re restoring a classic, outfitting an off-road rig, or replacing aging headlamp wiring. It’s ideal for do-it-yourself mechanics and professional installers who want a dependable, reversible conversion that eliminates flicker and protects both bulbs and factory wiring.