2019 Kenworth W900 Fuse Box Diagram & Amperage

Quick Answer

The 2019 Kenworth W900 typically has three primary fuse box locations:

• Under-Hood (Power Distribution Center): Located in the engine compartment, usually on the driver's side, near the firewall.
• In-Cab (Driver's Side Kick Panel): Located inside the cabin, behind the kick panel on the driver's side.
• Under Bunk/Sleeper (Chassis Power/Accessory Panel): Located within the sleeper compartment, commonly under the lower bunk.

The specific layout and numbering can vary slightly based on the truck's exact configuration and trim level. Always refer to the fuse diagram printed on the inside of your fuse box cover for the most accurate information.

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Under-Hood Fuse Box (Power Distribution Center)

This fuse box primarily houses high-amperage fuses and relays for critical engine and chassis functions. It's usually found on the driver's side of the engine bay, close to the firewall.

Common Fuses & Relays:

Fuse #	Amp	Color	Circuit / Component Protected
F1	15A	Blue	ECM (Engine Control Module) Power
F2	10A	Red	Ignition Switch
F3	20A	Yellow	Fuel Pump
F4	30A	Green	Starter Relay (Control)
F5	40A	Green	ABS (Anti-lock Braking System) Power
F6	15A	Blue	Headlight Low Beam (Left)
F7	15A	Blue	Headlight Low Beam (Right)
F8	20A	Yellow	Headlight High Beam (Left)
F9	20A Yellow	Headlight High Beam (Right)
F10	15A	Blue	Horn Relay
F11	25A	Clear	Blower Motor (HVAC)
F12	10A	Red	A/C Clutch Relay

Relay Locations (Under-Hood):

• Starter Relay: Controls the starter motor engagement.
• ECM Relay: Powers the Engine Control Module.
• Fuel Pump Relay: Controls power to the fuel pump.
• Headlight Relays: Separate relays for low and high beams, possibly left and right.
• ABS Relay: Powers the ABS module.
• Horn Relay: Activates the horn.

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In-Cab Fuse Box (Driver's Side Kick Panel)

Located inside the cab, typically behind a removable panel on the driver's side kick panel. This box usually contains fuses for interior accessories, lighting, and various control modules.

Common Fuses:

Fuse #	Amp	Color	Circuit / Component Protected
F1	10A	Red	Radio / Infotainment System
F2	15A	Blue	Cigar Lighter / 12V Power Outlet 1
F3	15A	Blue	Auxiliary Power Outlet (Dash)
F4	5A	Tan	Instrument Cluster
F5	10A	Red	Wiper Motor
F6	10A	Red	Washer Pump
F7	10A	Red	Tail Lights / Marker Lights
F8	10A	Red	Park Lights
F9	15A	Blue	Brake Lights (Stop Lamps)
F10	10A	Red	Turn Signals / Hazard Lights
F11	10A	Red	Dome Light / Interior Lighting
F12	5A	Tan	Airbag Control Module (SRS)
F13	20A	Yellow	Trailer Brake Control (If equipped)
F14	10A	Red	Cabin Fuse (General Accessories)
F15	15A	Blue	HVAC Control Head
F16	10A	Red	Power Windows
F17	10A	Red	Power Locks (If equipped)

Relay Locations (In-Cab/Dash):

• Accessory Relay: Often controls multiple accessory circuits.
• Wiper Relay: For windshield wiper operation.
• Turn Signal/Hazard Relay: Controls flasher functions.

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Under Bunk/Sleeper Fuse Box (Chassis Power/Accessory Panel)

This fuse panel is typically found within the sleeper compartment, often located under the lower bunk or behind an access panel. It primarily handles power distribution for sleeper accessories, auxiliary systems, and chassis-related components not directly under the hood.

Common Fuses:

Fuse #	Amp	Color	Circuit / Component Protected
F1	20A	Yellow	Sleeper Auxiliary Power Outlet
F2	15A	Blue	Refrigerator / Cooler (If equipped)
F3	10A	Red	Bunk Heater / HVAC Control
F4	15A	Blue	Interior Sleeper Lighting
F5	10A	Red	TV / Entertainment System (If equipped)
F6	20A	Yellow	Inverter (Auxiliary Power)
F7	10A	Red	Auxiliary Air Compressor (If equipped)
F8	15A	Blue	Chassis Power (General Sleeper)

Relays (Under Bunk/Sleeper):

• Sleeper Accessory Relay: Powers various sleeper amenities.
• Inverter Relay: For auxiliary power in the sleeper.

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How to Test a Fuse

Testing a fuse is a straightforward process that can help you quickly pinpoint electrical issues. Here's how:

1. Safety First: Ensure the ignition is off and disconnect the battery if you're working on high-amperage circuits.
2. Locate the Fuse: Find the suspected fuse in the appropriate fuse box using the diagrams above and, more importantly, your truck's specific fuse box lid legend.
3. Visual Inspection: Most modern fuses have a visible wire inside. If this wire is broken or melted, the fuse is blown and needs replacement.
4. Use a Fuse Puller: Gently remove the fuse using the plastic fuse puller usually found in the fuse box lid or tool kit.
5. Test with a Multimeter (Recommended):
   • Set your multimeter to the continuity or ohm setting.
   • Touch one probe to each metal terminal on the top of the fuse. Do not touch the plastic body.
   • A good fuse will show a reading of "0" or a very low resistance (indicating continuity). If it reads "OL" (Open Line) or "infinite resistance," the fuse is blown.
6. Test Light (Alternative):
   • With the circuit powered (ignition on for some circuits, but be cautious), connect the test light clip to a good ground.
   • Touch the probe of the test light to the small metal test points on the top of the fuse (if available). The light should illuminate on both sides of a good fuse. If it only illuminates on one side or not at all, the fuse is blown.
7. Replace: If the fuse is blown, replace it with a new fuse of the exact same amperage rating and type. Using a fuse with a higher amperage can cause severe electrical damage or fire.

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Common Blown Fuses on This Vehicle

While any fuse can blow, some are more commonly affected due to the nature of their circuits or connected accessories. On a 2019 Kenworth W900, consider these common culprits:

• Cigar Lighter / 12V Power Outlets: These fuses (often 15A or 20A) frequently blow due to overcurrent from charging multiple devices, using high-power accessories like small inverters or air compressors, or a short circuit in a connected device. Check first: Disconnect all devices from the outlets and replace the fuse. If it blows immediately, there