Replacing a headlight on a Peterbilt 379 can be straightforward, but choosing the correct part is not always as simple as ordering the first 379 headlight you find.
Depending on the condition of your truck, you may need only a bulb, a headlight housing, or a complete headlight assembly. You also need to confirm the correct side, mounting setup, and wiring before ordering.
This guide explains how to identify the right Peterbilt 379 headlight replacement, what to check for fitment, and when a complete assembly makes sense.
Big Truck Hoods carries a range of Peterbilt 379 replacement parts, including left- and right-hand headlight assemblies for 1987–2007 Peterbilt 379 trucks.
What Headlights Does a Peterbilt 379 Use?
The Peterbilt 379 is commonly associated with a traditional dual rectangular headlight configuration. However, many trucks on the road today have been modified over the years.
You may see 379s with:
- Halogen replacement assemblies
- LED conversions
- Custom housings
- Stainless or chrome housings
- Round-headlight conversions
- Modified brackets or wiring
Because of this, truck model and year should not be your only fitment checks.
Before ordering, compare the replacement with the assembly currently installed on your truck, especially the mounting points, wiring and overall configuration.
Peterbilt 379 Headlight Assembly vs. Housing vs. Bulb
One of the first things to determine is exactly what needs replacing.
Headlight Bulb
The bulb is the light source itself. If the housing, bracket and wiring are all in good condition and only the light has failed, a bulb replacement may be enough.
Headlight Housing or Bucket
The housing, sometimes called the bucket, supports and surrounds the headlight components.
It may need replacement if it is:
- Cracked
- Corroded
- Bent
- Missing mounting points
- Damaged in a collision
- No longer holding the lights securely
Complete Headlight Assembly
A complete assembly combines several components into one replacement unit.
The aftermarket Peterbilt 379 assemblies available from Big Truck Hoods include the headlight bucket assembly, hood bracket, wiring harness and halogen lights.
For example, the Peterbilt 379 left-hand headlight assembly is designed for the driver side, while the Peterbilt 379 right-hand headlight assembly covers the passenger side.
As a general rule:
- Replace the bulb if only the light source has failed.
- Replace the housing if the structural portion is damaged.
- Replace the complete assembly if several components are damaged.
Does the Same Headlight Fit Every Peterbilt 379?
Not necessarily.
The standard replacement assemblies carried by Big Truck Hoods are listed for 1987–2007 Peterbilt 379 models, but older trucks are often modified.
A previous owner may have changed:
- The headlight style
- The mounting bracket
- The wiring
- The connector
- The housing
That means two Peterbilt 379s from the same model year may not have identical headlight setups today.
The replacement assemblies discussed here use the following reference numbers:
| Position | OEM Reference | Listed Application |
|---|---|---|
| LH / Driver Side | 16-07572L-P | Peterbilt 379, 1987–2007 |
| RH / Passenger Side | 16-07572R-P | Peterbilt 379, 1987–2007 |
Use the OEM reference as one fitment check, but also compare the replacement with the part currently installed on the truck.
How to Identify the Correct Peterbilt 379 Headlight
Before ordering a replacement, check the following.
1. Confirm the Truck Model and Year
Verify that the truck is a Peterbilt 379 and note the model year. The replacement assemblies discussed in this guide are listed for 1987–2007 trucks.
2. Confirm the Correct Side
Peterbilt 379 headlight assemblies are side-specific.
- LH = left-hand / driver side
- RH = right-hand / passenger side
3. Check the Existing Part Number
Look for a label, stamping or reference number on the existing assembly or bracket. Compare that number with the replacement part.
4. Inspect the Existing Headlight Style
Check whether the truck still uses an original-style rectangular setup or has been modified with LED, round or custom lighting.
5. Check the Bracket and Wiring
Inspect for:
- Bent brackets
- Broken mounting points
- Spliced wires
- Damaged connectors
- Corrosion
- Previous lighting conversions
If the truck has been modified, a replacement assembly may not connect exactly as expected.
Peterbilt 379 Halogen vs. LED Headlights
Many 379 owners choose between traditional halogen lighting and LED upgrades.
Halogen Headlights
Halogen lighting is a practical choice for owners who want to stay close to the truck's existing setup.
Potential advantages include:
- Traditional appearance
- Straightforward replacement
- Replaceable bulbs
- Compatibility with many original-style housings
The Peterbilt 379 replacement assemblies carried by Big Truck Hoods include halogen lights.
You can browse additional semi-truck replacement headlights in the Big Truck Hoods headlight collection.
LED Headlights
LED conversions can offer a more modern appearance and may provide longer service life or lower power draw, depending on the product.
Before converting, check:
- Mounting compatibility
- Wiring
- Connectors
- Beam pattern
- Required adapters
- Road-use compliance
If your goal is simply to replace a damaged assembly, matching the truck's current setup is often the simplest option.
When Should You Replace the Complete Headlight Assembly?
A failed bulb does not automatically mean you need a complete assembly.
Consider replacing the full unit when:
- The housing is cracked
- Mounting points are broken
- The bracket is damaged
- Collision damage affects multiple components
- Corrosion is severe
- The headlight cannot be mounted securely
- The assembly cannot be aimed correctly
- Wiring or connectors are damaged along with the housing
If only the bulb has failed and the rest of the assembly remains in good condition, replacing the full unit may be unnecessary.
How to Replace a Peterbilt 379 Headlight Assembly
The exact process can vary depending on your truck's current setup and any previous modifications.
In general:
- Park the truck safely and switch off power.
- Inspect the existing mounting points and wiring before removal.
- Disconnect the wiring harness carefully.
- Remove the old assembly and mounting hardware.
- Compare the old and new assemblies before installation.
- Install the replacement without forcing brackets or connectors.
- Test the headlights.
- Check and adjust headlight aim.
If the mounting points or wiring look significantly different, verify the replacement before modifying either the truck or the new assembly.
Common Peterbilt 379 Headlight Replacement Problems
The New Headlight Doesn't Line Up
Check whether:
- You ordered the correct side
- The bracket is bent
- The truck has collision damage
- The mounting setup has been modified
The Connector Doesn't Match
This may indicate previous wiring changes or an aftermarket conversion.
Avoid cutting the replacement harness until you have confirmed the correct part.
One Headlight Sits at a Different Angle
Inspect the mounting bracket, hardware and surrounding body area for damage.
Moisture Keeps Getting Inside
Repeated moisture may point to a damaged housing, failed seal or lens issue.
Should You Replace Both Headlights at the Same Time?
Not always.
If one assembly is damaged and the other remains in good condition, replacing only the damaged side may be enough.
Replacing both may make sense when:
- Both assemblies are heavily aged
- Both housings are deteriorating
- Light output differs noticeably
- You are converting both sides to a new lighting system
- You want both sides to match visually
Peterbilt 379 Headlight Fitment Checklist
Before ordering, confirm:
- Peterbilt 379 model
- Model year
- LH or RH side
- Existing headlight style
- OEM/reference number
- Mounting bracket condition
- Wiring and connector
- Previous modifications
- Whether you need a bulb, housing or complete assembly
A few minutes spent checking these details can help avoid ordering the wrong part.
Shop Peterbilt 379 Replacement Headlights
Big Truck Hoods carries aftermarket replacement headlight assemblies for 1987–2007 Peterbilt 379 trucks.
Shop the Peterbilt 379 LH headlight assembly for the driver side or the Peterbilt 379 RH headlight assembly for the passenger side.
You can also browse the full range of Peterbilt 379 replacement parts and semi-truck headlights.
For more Peterbilt fitment information, see our Peterbilt 388 vs. 389 guide and Peterbilt 377 hood conversion guide.
Peterbilt 379 Headlight Replacement FAQs
What years does the Peterbilt 379 headlight assembly fit?
The replacement assemblies discussed in this guide are listed for 1987–2007 Peterbilt 379 trucks.
Are Peterbilt 379 left- and right-hand headlights the same?
No. The assemblies are side-specific. LH refers to the driver side and RH refers to the passenger side.
What are the Peterbilt 379 headlight OEM reference numbers?
The references discussed in this guide are 16-07572L-P for the left-hand side and 16-07572R-P for the right-hand side.
Can you put LED headlights on a Peterbilt 379?
Yes, aftermarket LED options are available, but mounting, wiring, connectors and compatibility should be checked before converting.
Do I need to replace the entire headlight assembly?
Not always. If only the bulb has failed and the housing, bracket and wiring are still in good condition, a complete assembly may not be necessary.