2008–2026 Cascadia H11 low, high and fog LED bulbs
BTS has confirmed that our current Alpha, Morimoto and GTR H11 bulbs fit the original bulb-type low beam, high beam and fog-light positions on the 2008–2026 Freightliner Cascadia. These bulbs do not replace factory LED headlights or factory LED fog lamps. Identify each position independently, including whether fog lights are fitted.
Alpha Series H11 · Morimoto 2Stroke 4.0 H11 pair · GTR Ultra 3.0 H11 pair.
Each position takes one pair of bulbs. Low beam, high beam and fog lights use separate bulbs even though they all use H11. Replacing all three fitted positions takes six H11 bulbs in total. The Morimoto and GTR offers shown are pairs; check the package contents of the selected Alpha listing when ordering the required two bulbs.
LED headlight conversion bulbs may not comply with FMVSS/CMVSS requirements for on-road use. Check applicable state and provincial laws before use.
2008–2026 Cascadia 3157 front-signal LED options
BTS has also confirmed our current Alpha, Morimoto and GTR 3157 LED options for the original replaceable front signals across 2008–2026. The complete front-signal position takes two bulbs — one pair. Choose amber output for this position.
Alpha 3157 Amber pair · Morimoto XB 3157 Amber pair · GTR Carbide 2.0 Non-CK Amber pair · GTR Carbide 2.0 CK Amber pair.
The GTR page offers different wiring versions: choose the matching CK or Non-CK Amber option. Morimoto specifies that its XB bulbs are not compatible with PWM-driven DRL circuits. Follow the selected bulb’s installation instructions; these are product-specific details, not a statement that every Cascadia uses that DRL circuit.
How many Cascadia bulbs do I need?
| 2008–2026 original bulb-type position | Confirmed LED replacement | Complete position |
|---|---|---|
| Low beam | H11 | 2 bulbs — one pair |
| High beam | H11 | 2 bulbs — one pair |
| Fog lights, where fitted | H11 | 2 bulbs — one pair |
| Front turn signals | 3157 LED family, amber | 2 bulbs — one pair |
These counts come from BTS’s confirmed installations on the original bulb-type equipment. They are vehicle quantities, separate from how a seller packages an offer. The same H11 size does not combine the low, high and fog positions into one pair.
Optional electrical accessory: Alpha PWM modules are separate accessories for an actual compatible flicker or bulb-out issue. Use the matching H11 connector and the listed 9–16V DC range; the modules are not automatically required by the bulb fitment above.
Freightliner original-lamp references
Freightliner’s manual retains the original codes below. Its turn/marker entry is 3457 (GE 3457); BTS’s confirmed 3157 LED replacement above is separate product-fit evidence. The factory manual does not supply the 2008–2026 year range or the pair quantities; those are the BTS installation confirmations.
| Light Type | OEM Bulb Size |
|---|---|
| Headlight low beam | H11 |
| Headlight high beam | H11 |
| Fog / driving lamps, where fitted | H11 |
| Turn / marker lamp in original headlight | 3457 (GE 3457) |
| Incandescent auxiliary turn lamp on fender | GE 2058U |
| Integral stop / tail / backup lamp group | GE 1157 / GE 1156 — listed together |
| Utility light | WEE 199 |
Fender, rear and utility lamps
The incandescent auxiliary turn lamp on the fender is a separate position from the turn/marker bulb inside the headlight. Freightliner lists GE 2058U for that fender lamp.
For the integral stop, tail and backup lamps, the manual lists GE 1157 / GE 1156 together. It does not assign each reference to an individual function in that table. Match the removed bulb and the installed rear lamp before choosing a replacement.
The utility-light reference is WEE 199. Utility lamps can be mounted in several places on the cab, exhaust support or sleeper; use the reference for the lamp actually fitted.
If your headlights have been changed, use the installed assembly’s specifications. These references are for the named United Pacific housings.
| Assembly | Low beam | High beam | Signal |
|---|---|---|---|
| 31320 OE-style passenger headlight | H11, 55 W | H11, 55 W | 4157 |
| 31226 / 31227 / 31228 / 31229 projection headlights with amber position lights | H7, 55 W | H1, 55 W | 3157NAK |
The 31226 family also requires wiring for its amber LED position-light bars. For an LED bulb conversion, compare Alpha Series H7 bulbs and Alpha Series H1 Micro bulbs with the housing’s retention system, rear cover and available clearance.
Manufacturer references: United Pacific 31320 and United Pacific 31226 family.
2008-2017 Freightliner Cascadia
Prefer a complete headlight upgrade? Shop assemblies for the 2008–2017 Freightliner Cascadia and compare the exact application, side, lighting functions and installation notes.
Shop NowCommon Cascadia bulb questions
For the original halogen configuration described here, start with H11 for low beam and H11 for high beam. Check the installed lamp on your truck; a replacement headlight can use different bulbs. The United Pacific comparison above identifies two such housing families.
Yes. Both OEM bulb positions use H11, with a separate bulb for each beam. An aftermarket headlight assembly may use different sizes, as shown in the United Pacific reference above.
Use H11 as the OEM bulb specification. If an LED product groups several bulb sizes together, confirm that the exact product supports the H11 socket and fits your headlight housing.
Factory references: Freightliner Cascadia Driver’s Manual, Table 26.8 (printed page 26.3), Fig. 5.3 and utility-light description, STI-478-6, revision 02/03/2022. These are lamp-configuration references; the manual does not give a model-year range or bulb quantities for this table. References checked September 2026. Use the installed assembly’s instructions if the housings have changed.