Why Choose Morimoto Sealed4 for Your Peterbilt 379?
The Peterbilt 379 runs a dual 4×6 sealed beam configuration per side. Factory sealed beams are functional — but outdated in performance and beam control.
The Morimoto Sealed4 brings modern projector LED performance into the exact 4×6 footprint your 379 already uses.
If you’re looking for:
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A true LED upgrade without custom fabrication
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Wider beam coverage for highway driving
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Cleaner cutoff with less glare
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Quad beam potential using your factory 4-headlight setup
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Plug-and-play H4 compatibility
This is one of the strongest 4×6 LED upgrades available for the 379 platform.
Key Features & Benefits
True Bi-LED Optics in Each Housing
Each Sealed4 unit contains both low and high beam functionality.
Instead of relying on separate dedicated low/high sealed beams, each Morimoto housing uses:
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Nichia NCSW170C LEDs
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Kuria Optic projector lens array
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Precision LHD stepped beam pattern
Output:
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2,400 lumens (Low Beam)
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4,300 lumens (High Beam)
You get modern projector clarity in a factory 4×6 size.
Quad Beam Capability for Dual 4×6 Peterbilt 379 Setups
The Peterbilt 379’s dual 4×6 configuration allows for quad beam functionality.
With a simple low-beam feed jumper to the unused H4 high-beam pin, you can activate:
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Quad low beam
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Quad high beam
When all four headlights fire on high beam, forward visibility dramatically increases — ideal for:
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Open highway driving
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Long-haul night routes
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Rural and low-visibility environments
Modified wiring configurations may affect compliance. Always verify legality in your area.
Massive Beam Width for Real-World Driving
One of the standout characteristics of the Sealed4 is lateral beam coverage.
Compared to reflector-style sealed beams, projector optics provide:
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Strong edge illumination
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Even foreground fill
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Reduced scatter
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Defined beam cutoff
This makes a noticeable difference on curved roads and unlit highways.
Plug-and-Play H4 Installation on Peterbilt 379
The Sealed4 includes an H4 3-pin male connector and replaces standard 4×6 sealed beam sizes:
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H4656
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H4651
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H4652
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H4666
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HP4656
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HP4651
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HP4666
On most Peterbilt 379 trucks:
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Remove factory sealed beam
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Plug in Sealed4
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Reinstall in OEM housing
No external relay harness required in most applications.
Built for Commercial-Duty Use
Designed for longevity and durability:
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Die-cast aluminum housing (acts as heat sink)
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UV-coated polycarbonate lens
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Integrated PWM LED driver
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LHD traffic pattern optics
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5-Year limited warranty through Morimoto
This is not a budget reflector conversion. It is a purpose-built projector LED headlight.
Technical Specifications
Light Source: Nichia NCSW170C – 5000K
Low Beam Intensity: 2,400 lumens
High Beam Intensity: 4,300 lumens
Power Draw: 20W (Low) / 35W (High)
Input: H4 3-pin
Housing Material: Aluminum
Lens Material: UV-coated Polycarbonate
Traffic Pattern: LHD
Warranty: 5 Years
When installed as designed, the Sealed4 meets FMVSS 108 standards. Compliance may vary depending on installation and wiring configuration.
Compatibility
Designed to replace standard 4×6 rectangular sealed beam headlights.
Direct-fit for:
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Peterbilt 379 (dual 4×6 configuration)
Also compatible with other trucks using 4×6 sealed beams, but this listing is optimized specifically for Peterbilt 379 applications.
What’s Included
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1x Morimoto Sealed4 4×6 Bi-LED Headlight
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Integrated H4 male connector
Frequently Asked Questions About Morimoto Sealed4 for Peterbilt 379
Will this fit my Peterbilt 379?
Yes. The Peterbilt 379 uses dual 4×6 sealed beam headlights. The Morimoto Sealed4 is a direct H4 plug-and-play replacement.
Is this brighter than factory sealed beams?
Yes. With 2,400 lumens low beam and 4,300 lumens high beam output, the Sealed4 significantly outperforms traditional halogen sealed beams.
What is quad beam mode on a Peterbilt 379?
Quad beam mode allows all four 4×6 headlights to operate together on low and high beam. A simple jumper modification enables this configuration.
Do I need a relay harness?
In most Peterbilt 379 applications, no additional relay harness is required. The integrated PWM driver regulates current internally.
Is this street legal?
When installed as designed, the Sealed4 meets FMVSS 108 standards. Modified wiring configurations may change compliance.
