2020 Kenworth W900 Bulb Size Guide
AI-generated reference. Always verify torque values, fluid capacities, intervals, and procedures against the manufacturer's service manual or OEM repair information before performing work. Repairius is not liable for damage from acting on this content without verification.
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Quick Reference
| Location | Bulb Size | Type |
|---|---|---|
| Low Beam Headlight | H11, H7 | Halogen (some trims) |
| High Beam Headlight | H1, H7 | Halogen (some trims) |
| Fog Light | H10, H11 | Halogen |
| DRL | 3157 | Incandescent |
| Front Turn Signal | 3157 Amber, LED | Incandescent/LED |
| Rear Turn Signal | 3157 Amber, LED | Incandescent/LED |
| Brake Light | 3157 Red, LED | Incandescent/LED |
| Tail Light | 3157 Red, LED | Incandescent/LED |
| Reverse Light | 3157 White, LED | Incandescent/LED |
| License Plate | 168, LED | Incandescent/LED |
| Side Marker | 194, LED | Incandescent/LED |
| Dome/Map Light | 921, 194, LED | Incandescent/LED (trim dependent) |
The 2020 Kenworth W900, a legendary workhorse in the trucking industry, offers a blend of classic styling and modern technology. When it comes to lighting, you'll find a mix of traditional halogen and incandescent bulbs alongside available LED options, often varying by trim level and specific factory configurations. Understanding the correct bulb sizes and types is crucial for maintenance, repairs, and when considering upgrades.
For headlights, many W900 models come equipped with a dual-bulb halogen system, often utilizing H11 or H7 for low beams and H1 or H7 for high beams depending on the specific headlamp assembly. Some premium packages or custom builds may feature factory-installed LED headlamps, which are typically integrated units and not serviceable with individual bulbs. Fog lights commonly use H10 or H11 halogen bulbs.
Daytime Running Lights (DRLs), front and rear turn signals, brake lights, and tail lights often use 3157 incandescent bulbs from the factory. However, due to the W900's popularity for customization and fleet specification, many trucks will have factory or aftermarket LED equivalents for these functions. Reverse lights also commonly use 3157 bulbs or integrated LEDs. Smaller exterior lights such as license plate lights and side markers typically employ 168 or 194 incandescent bulbs, with LED upgrades being a popular choice for improved visibility and longevity.
Inside the cab, dome and map lights can vary, often utilizing 921 or 194 incandescent bulbs, but LED interior lighting packages are also common, providing a brighter and more modern ambiance.
LED vs Halogen Upgrade Considerations
Upgrading from halogen or incandescent bulbs to LEDs for your 2020 Kenworth W900 can offer several benefits, including improved brightness, longer lifespan, and a more modern appearance. However, there are a few important considerations:
- CANBUS Errors: Many modern heavy-duty trucks, including the W900, incorporate a CANBUS (Controller Area Network Bus) system that monitors bulb resistance. Incandescent bulbs draw more power than LEDs, leading to a lower resistance. When you replace an incandescent bulb with an LED, the lower power draw can cause the CANBUS system to detect an
More specs for the 2020 Kenworth W900
Oil Capacity & Filter
Capacity, weight, filter PN, drain plug torque, change interval.
Fluid Type Specs
Engine oil, coolant, ATF, diff, brake, PS, DEF — with OEM spec numbers.
Coolant Capacity & Type
Total system capacity, OEM coolant spec, flush interval, bleed tips.
Transmission Fluid & Service
Trans model, fluid spec, capacity, filter PN, service interval.
Torque Specifications
Lug nuts, drain plug, caliper, axle nut, plug, key fasteners.
Brake Pad & Rotor Specs
Pad PNs, rotor size, min thickness, caliper torque.
Tire Size & Pressure
OEM size, cold psi, bolt pattern, wheel size, TPMS.
Battery Size & Group
Group size, CCA, AGM/flooded, dimensions, reset note.
A/C Refrigerant & Oil
R-134a or R-1234yf, charge oz, PAG oil spec.
Factory Maintenance Schedule
Service intervals by mileage, severe-duty notes, known issues.
Towing Capacity & Payload
Max tow, payload, GVWR/GCWR, hitch class by trim.
Fuse Box Diagram & Amperage
Fuse box locations, layout, amps, and what each fuse controls.
Serpentine Belt Routing & Length
Belt routing, length, rib count, OEM + aftermarket PNs.
Wheel Alignment Specifications
Camber, caster, toe ranges (front & rear), adjustability notes.
Paint Color Codes
All factory colors with paint codes, sticker location, touch-up tips.
Wiper Blade Sizes
Driver/passenger/rear blade size, attachment, OEM + cross-refs.
Spark Plug Type & Gap
Plug PN, gap, torque, interval by engine.
Transmission & Axle Gear Ratios
Trans gear ratios, axle ratios, RPO codes, tow vs MPG impact.
Key Fob Programming
DIY programming steps, FCC ID, fob PN, battery, transponder.
Same spec — other model years
Maintenance & repair guides
2020 Kenworth W900 Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
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