What This Headlight Is
P54-6157-100R is a complete right-side headlight assembly, not a bulb. The LED light source, projector optic, LED stripe and high-beam function are all built into one sealed housing. You replace the whole unit. There is no serviceable bulb behind the lens, so a burned-out section or a moisture-fogged reflector means the assembly comes off the truck.
The housing is IP67 sealed, which matters on a truck that sees pressure washers at the wash bay and constant road spray off the drive tires. Cold-white LED output gives sharper edge definition on the beam cutoff than an aged halogen, and the projector optic keeps the hot spot down where it belongs instead of throwing glare at oncoming traffic.
Wiring is plug-and-play through the factory connectors, with load resistors built into the harness so the truck's lighting circuit does not read the lower LED draw as an open. Rated LED life is over 50,000 hours. On a linehaul truck running nights, that generally outlasts several rounds of halogen capsules.
Why These Numbers Cross
Elite Truck Parts ETP-P54-6103-10000R/L and Newstar S-27798 appear in cross-reference tables against P54-6157-100R because all three describe the same physical lamp: a 12V LED projector headlight assembly built to drop into the Kenworth T660 and T680 headlight opening using the same mounting points and the same connector interface.
Aftermarket suppliers each carry their own catalog prefix, so the same tooling shows up under a different number depending on who boxed it. The ETP number carries an R/L suffix because that supplier lists the left and right hands under one base number. Ours splits them, and the trailing R on P54-6157-100R is the side call-out — right side.
Those numbers are listed here for identification only. PartStop is not affiliated with, endorsed by, or authorized by any OEM manufacturer. A cross-reference is a starting point, not a fitment guarantee. Confirm by VIN or by reading the number stamped or labeled on the assembly you are pulling off the truck.
Check Before You Order
First, confirm the side. Right side means the passenger side as you sit in the seat facing forward. Ordering the wrong hand is the most common mistake on headlight assemblies, and a left housing will not line up with the right-side mounting tabs. If a previous repair swapped in a mismatched lamp, go by the opening, not by what is currently installed.
Second, verify the failure is actually the lamp. Check the connector for green corrosion and spread terminals, check ground integrity at the chassis, and check the headlight switch and any body control fuses. A dead LED assembly and a corroded pin look identical from the driver's seat. Load-test the circuit before you pull the housing.
P54-6157-100R Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to P54-6157-100R. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Elite Truck Parts | ETP-P54-6103-10000R/L |
| Newstar | S-27798 |
Frequently asked questions
Does P54-6157-100R come with the bulb, or do I reuse mine?
It is a complete assembly. The LED light source is integrated into the sealed housing and is not serviceable separately, so there is nothing to transfer from the old unit. You install the assembly and connect it to the factory harness. If your old lamp used a replaceable capsule, that capsule is not reused here.
Will I get a hyperflash or bulb-out warning after installing an LED assembly?
The harness on this unit has load resistors built in, which is what normally prevents a low-draw LED from tripping a bulb-out or fast-flash condition. Behavior still depends on how your specific truck is wired and what body electronics it carries. If a warning appears after install, check the ground and connector before assuming the lamp is at fault.
How do I know this is the right part for my T680 without guessing?
Pull the existing right-side assembly and read the number molded or labeled on the housing, then compare it against P54-6157-100R and the listed cross numbers. If the old lamp is unreadable or already a replacement, verify by VIN. Cross-reference gives you a strong starting point but does not confirm fitment on its own.
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