Simple, Reliable LED Upgrade for 4×6 Headlights
This ULTRALIT 4×6 LED series offers separate low-beam and high-beam versions. Select the beam function that matches the lamp position, then verify the connector and fitment.
Key Features & Benefits
Improved Visibility with White LED Output
Produces white light at the stated colour temperature. Colour temperature describes the light’s appearance, not visibility in poor weather.
Available in High Beam & Low Beam Configurations
Choose the correct beam type for your setup:
- Low Beam (Item #31396): 400 lumens, 0.80A @ 12.8V
- High Beam (Item #31397): 550 lumens, 1.10A @ 12.8V
These can be paired together for a complete headlight system upgrade.
Durable Solid-State Construction
- Die-cast aluminum housing for heat dissipation
- Shock and vibration resistant design
- Polycarbonate lens protects against debris and road hazards
Built to handle real-world trucking conditions.
Direct 4×6 Sealed Beam Replacement
Designed to replace standard 4″ x 6″ sealed beam headlights used in many heavy-duty trucks, including older Peterbilt models such as the Peterbilt 379.
Dual Voltage Compatibility
Supports both 12V and 24V systems, making it suitable for a wide range of semi trucks and commercial vehicles.
Performance & Technical Specs
Low Beam (Item #31396):
- Output: 400 lumens
- Current: 0.80A @ 12.8V
- Beam Type: Low Beam
High Beam (Item #31397):
- Output: 550 lumens
- Current: 1.10A @ 12.8V
- Beam Type: High Beam
Shared Specs:
- Headlight Size: 4″ x 6″
- Voltage: 12–24V
- Compliance: DOT/SAE, FMVSS 108
Installation Notes
- Plug-and-play for standard 4×6 connections
- Load resistor may be required for proper operation (Item #34205)
- Fits into factory headlight housings
Professional installation recommended for optimal aiming and performance.
Built for Work Trucks and Daily Drivers
This ULTRALIT series focuses on durability and function over styling. Ideal for fleet vehicles, daily drivers, or anyone needing a dependable LED upgrade without added features like position lights.
What’s Included
- (1) ULTRALIT 4×6 LED Headlight (High or Low Beam depending on selection)
Frequently Asked Questions About 4×6 LED Headlights
What’s the difference between high beam and low beam?
Low beams are designed for regular nighttime driving without blinding other drivers, while high beams provide maximum forward visibility when no oncoming traffic is present.
Can I replace sealed beam headlights with LED?
Yes, these are designed as direct replacements for standard 4×6 sealed beam headlights.
Do I need both high and low beam units?
Yes, most vehicles require both a high beam and low beam for proper headlight functionality.
Will these fit my truck?
They fit standard 4×6 headlight applications commonly found on older semi trucks. Fitment may vary depending on your setup.
Do LED headlights require resistors?
In some cases, a load resistor may be required to prevent flickering or compatibility issues.
Are these headlights DOT compliant?
United Pacific lists DOT/SAE and FMVSS 108 conformity for the specified lamp. Confirm the correct application, installation and aim.
Are these brighter than halogen headlights?
They use LED light sources. Compare the specifications of the selected low- or high-beam version; white colour alone does not establish better visibility.
Can these run on 24V systems?
Yes, they are compatible with both 12V and 24V systems.
Compare compatible headlight options
Browse Peterbilt 379 Headlights and compare the listed housing, wiring and beam functions for your truck.
