2016 Kenworth W900 Fuse Box Diagram & Amperage

Quick Answer

The 2016 Kenworth W900 typically has multiple fuse box locations to manage the complex electrical systems of a heavy-duty truck. You'll generally find fuse boxes in the following locations:

• Under-hood: Often located on the driver's side, near the firewall, or integrated into a power distribution center.
• Dash Kick-Panel: Frequently located on the passenger side, behind a removable panel.
• Sleeper/Cab Rear Wall: Some models may have an additional fuse panel in the sleeper compartment or on the rear wall of the cab, especially for accessory circuits.

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Under-hood Fuse Box / Power Distribution Center

The under-hood fuse box, often part of a larger power distribution center, houses fuses and relays for critical engine functions, lighting, and heavy-draw accessories. Always verify the exact layout with the diagram printed on the inside of your fuse box lid, as configurations can vary slightly.

Fuse #	Amp	Color	Circuit / Component Protected
F1	15A	Blue	ECM (Engine Control Module) Power
F2	15A	Blue	Fuel Pump Relay
F3	10A	Red	Ignition Switch
F4	10A	Red	Starter Relay
F5	20A	Yellow	Headlights (Low Beam - Left)
F6	20A	Yellow	Headlights (Low Beam - Right)
F7	20A	Yellow	Headlights (High Beam - Left)
F8	20A	Yellow	Headlights (High Beam - Right)
F9	10A	Red	Tail Lights / Marker Lights
F10	15A	Blue	ABS (Anti-lock Braking System) Controller
F11	20A	Yellow	Blower Motor High
F12	10A	Red	A/C Clutch Relay
F13	30A	Green	Trailer Brake Controller Power
F14	15A	Blue	Diagnostic Port / Data Link Connector

Relay Locations (Common):

• ECM Relay: Powers the Engine Control Module.
• Fuel Pump Relay: Controls power to the fuel pump.
• Starter Relay: Engages the starter motor.
• Headlight Relays: Separate relays for low and high beams.
• Blower Motor Relay: Controls the HVAC blower.
• A/C Clutch Relay: Engages the air conditioning compressor clutch.
• Trailer Brake Relay: Provides power for the trailer braking system.

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Dash Kick-Panel Fuse Box (Passenger Side)

This fuse box typically contains fuses for interior accessories, gauges, radio, and other cabin-related electrical components. Again, refer to your specific vehicle's fuse diagram for precise details.

Fuse #	Amp	Color	Circuit / Component Protected
F1	10A	Red	Radio / Infotainment System
F2	15A	Blue	HVAC Control Module
F3	20A	Yellow	Cigar Lighter / 12V Power Outlet (Dash)
F4	10A	Red	Instrument Cluster
F5	10A	Red	Turn Signals / Hazard Lights
F6	15A	Blue	Wiper Motor
F7	10A	Red	Horn
F8	15A	Blue	Brake Lights / Stop Lamps
F9	11	10A	Red
F10	20A	Yellow	Power Windows (If equipped)
F11	10A	Red	Airbag Control Module (SRS)
F12	15A	Blue	Heated Mirrors (If equipped)

Relay Locations (Common):

• Accessory Relay: Powers various interior accessories.
• Wiper Relay: Controls the windshield wipers.
• Brake Light Relay: Controls the brake lamps.

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Sleeper / Cab Rear Wall Fuse Box (If Equipped)

Some Kenworth W900 models, especially those with extensive sleeper amenities, may include an additional fuse panel in the sleeper area. This panel typically powers bunk heaters, refrigerators, additional power outlets, and other sleeper comforts.

Fuse #	Amp	Color	Circuit / Component Protected
F1	20A	Yellow	12V Power Outlet (Sleeper)
F2	15A	Blue	Bunk Heater / HVAC (Sleeper)
F3	10A	Red	Refrigerator (If equipped)
F4	10A	Red	Interior Sleeper Lights
F5	20A	Yellow	Auxiliary Power Inverter (If equipped)
F6	15A	Blue	CB Radio / Communications Equipment

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How to Test a Fuse

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

1. Safety First: Ensure the ignition is off and the vehicle is not running. For under-hood fuses, disconnect the battery's negative terminal for extra safety.
2. Locate the Fuse Box: Refer to the above sections to find the relevant fuse box.
3. Identify the Suspect Fuse: Look at your fuse box diagram (usually on the lid) to find the fuse for the circuit that's not working.
4. Visual Inspection: Pull the fuse straight out. Most modern blade-type fuses have a small wire visible through the clear plastic. If this wire is broken or melted, the fuse is blown. A blown fuse will appear discolored or have a visible gap.
5. Use a Multimeter (Recommended):
   • Set your multimeter to the continuity or ohms (resistance) setting.
   • Touch the probes to the two metal blades on top of the fuse.
   • If the fuse is good, the multimeter will show a reading close to zero ohms (continuity) or beep if it has an audible continuity tester.
   • If the fuse is blown, the multimeter will show an "OL" (open circuit) or no reading, indicating no continuity.
6. Replace the Fuse: If the fuse is blown, replace it with a new fuse of the exact same amperage rating and physical size/type. Never use a higher-rated fuse, as this can lead to serious electrical damage or fire.

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Common Blown Fuses on This Vehicle

On a heavy-duty truck like the Kenworth W900, certain circuits tend to experience blown fuses more often due to usage or potential issues. If you have a component not working, always check the fuse first.

• Cigar Lighter / 12V Outlets: These are frequent culprits, especially if you're plugging in high-draw accessories (inverters, chargers, heating blankets). Check for foreign objects (coins, paper clips) shorting out the outlet.
• Blower Motor: A failing blower motor can draw excessive current and blow its fuse. If your fan only works on certain speeds or not at all, check this fuse. A clogged cabin air filter can also put strain on the motor.
• Trailer Brake / Marker Lights: Due to the external connections and exposure to elements, trailer wiring can often short out, leading to blown fuses for these circuits. Inspect your trailer's wiring harness and connection point.
• Headlights: While less common, a short in the headlight wiring or a faulty bulb can occasionally blow a headlight fuse. Check both bulbs if one light is out.
• Radio / Infotainment: If your radio suddenly goes dead, a blown fuse is often the simplest explanation. This can happen due to a spike in voltage or an internal short in the unit.

Always check the easiest things first: Before diving into complex diagnostics, verify the fuse for the non-working component. Often, a simple fuse replacement is all that's needed.

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