2023 International LT — Fuse Box Diagram & Amperage

Quick Answer

The 2023 International LT features multiple fuse boxes located throughout the vehicle to manage its extensive electrical systems. You'll find fuse boxes in the following locations:

• Under-hood: Typically on the driver's side, near the firewall or fender.
• Dash Kick-Panel (Interior): Usually located on the passenger side, behind a removable panel.
• Battery Box (Chassis): Often found within or adjacent to the battery box, usually on the driver's side of the frame rail.

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Under-Hood Fuse Box

The under-hood fuse box on the 2023 International LT typically houses fuses and relays for major powertrain components, lighting, and auxiliary systems. This box is critical for engine operation and exterior functions.

Note: Fuse configurations can vary slightly due to trim levels and optional equipment. Always refer to the legend on your fuse box lid for the most accurate information.

Fuse #	Amp	Color	Circuit / Component Protected
F1	15A	Blue	ECM (Engine Control Module) - Switched Power
F2	10A	Red	ECM (Engine Control Module) - Constant Power
F3	20A	Yellow	Fuel Pump Relay / Circuit
F4	30A	Green	ABS (Anti-lock Brake System) Module
F5	10A	Red	Ignition Switch Input
F6	25A	Clear	Starter Solenoid / Relay
F7	20A	Yellow	Headlights - Low Beam (Left)
F8	20A	Yellow	Headlights - Low Beam (Right)
F9	15A	Blue	Headlights - High Beam (Left)
F10	15A	Blue	Headlights - High Beam (Right)
F11	10A	Red	Parking Lights / Tail Lights (Left)
F12	10A	Red	Parking Lights / Tail Lights (Right)
F13	15A	Blue	Trailer Brake Controller Power
F14	20A	Yellow	Trailer ABS Power
F15	25A	Clear	Blower Motor - HVAC
F16	10A	Red	A/C Clutch Relay
F17	30A	Green	Main Power Distribution

Common Relays in this Box:

• R1: Fuel Pump Relay
• R2: Starter Relay
• R3: Headlight Low Beam Relay
• R4: Headlight High Beam Relay
• R5: A/C Clutch Relay
• R6: ECM Power Relay

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Dash Kick-Panel Fuse Box (Interior)

This interior fuse box, typically found on the passenger side kick panel, manages accessories, interior lighting, and various convenience features. It's often protected by a removable plastic trim piece.

Note: Always verify the fuse legend printed on your fuse box cover for precise circuit identification.

Fuse #	Amp	Color	Circuit / Component Protected
F1	10A	Red	Radio / Infotainment System
F2	15A	Blue	Cigar Lighter / 12V Power Outlet (Dash)
F3	15A	Blue	HVAC Control Module / Blower Fan Control
F4	10A	Red	Interior Dome Lights / Reading Lights
F5	5A	Tan	Instrument Cluster / Gauges
F6	20A	Yellow	Auxiliary Power Outlet (Console)
F7	10A	Red	Windshield Wipers / Washer Pump
F8	5A	Tan	ABS Warning Lamp / Brake Switch Input
F9	10A	Red	Airbag (SRS) Control Module
F10	15A	Blue	Power Windows (Driver & Passenger)
F11	10A	Red	Power Locks Control
F12	20A	Yellow	Trailer Brake Controller (Cabin Power)
F13	25A	Clear	HVAC Blower Motor - Secondary (if equipped)
F14	10A	Red	Diagnostic Port (OBD-II)
F15	15A	Blue	Auxiliary Switches / Upfitter Switches (if any)

Common Relays in this Box:

• R1: Accessory Power Relay
• R2: Wiper Motor Relay

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Battery Box Fuse Panel (Chassis)

Some 2023 International LT trucks feature a primary fuse and circuit breaker panel located near the batteries on the chassis. This box often contains high-amperage fuses and circuit breakers for major power distribution to the entire truck's electrical system, including body builders' connections and main power feeds.

Note: This location might contain primarily high-amperage circuit breakers rather than traditional fuses. Always look for a legend or diagram near the batteries.

Fuse/Breaker #	Amp	Color	Circuit / Component Protected
CB1	150A	(N/A)	Main Chassis Power Distribution
CB2	80A	(N/A)	Body Builder/Auxiliary Power
F1	50A	Red	ABS System Main Power
F2	40A	Green	Trailer Power (Constant)
F3	30A	Green	Lift Gate Power (if equipped)
F4	20A	Yellow	ECM Main Power Feed

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How to Test a Fuse

Testing a fuse is a straightforward process that can help you diagnose electrical issues quickly. You'll need a fuse puller (usually found in the fuse box lid) and a multimeter or a 12V test light.

1. Locate the fuse box: Refer to the "Quick Answer" section for locations.
2. Turn off the ignition: Ensure the vehicle is off to prevent electrical shorts.
3. Identify the suspected fuse: Use the diagrams above and the fuse box lid legend to find the fuse for the circuit you're troubleshooting.
4. Carefully remove the fuse: Use the fuse puller. Avoid using pliers, which can damage the fuse.
5. Visually inspect the fuse: Hold it up to the light. If the metal wire or strip inside is broken or discolored, the fuse is blown and needs replacement.
6. Test with a multimeter (recommended):
   • Set your multimeter to the continuity or ohm setting.
   • Touch one probe to each metal blade of the fuse.
   • A good fuse will show a reading close to zero ohms or indicate continuity (beep, depending on your multimeter). A blown fuse will show an open circuit or no continuity.
7. Test with a 12V test light:
   • Clip the alligator clip of the test light to a good ground point on the vehicle's chassis.
   • With the fuse still in its slot, touch the probe of the test light to the small metal test points on the top of the fuse (most modern fuses have these).
   • With the ignition on (and the circuit active, if applicable), the test light should illuminate on both test points. If it lights up on one side but not the other, the fuse is blown. If it doesn't light up on either side, there's no power to the circuit, or the ignition is not on.
8. Replace the fuse: If blown, replace it with a new fuse of the exact same amperage rating and type. Installing a higher-rated fuse can cause serious electrical damage or fire.

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Common Blown Fuses on this Vehicle

While any fuse can blow, certain circuits on heavy-duty trucks like the International LT are more prone to issues due to their constant use or exposure to various conditions.

• Cigar Lighter / 12V Outlets: Often blown by faulty phone chargers, air compressors, or other high-drain accessories. If your accessories aren't working, check the interior fuse box for these fuses first.
• Trailer Brake / Trailer ABS Fuses: These circuits are under constant stress when towing and can be affected by shorts in trailer wiring or issues with the trailer brake controller. If you're experiencing trailer light or brake issues, check the under-hood and dash kick-panel fuses related to the trailer.
• Headlight Fuses: Especially with older bulb types or if you frequently operate in harsh conditions, headlights can occasionally blow fuses. If one or both headlights are out, these are a good place to start in the under-hood fuse box.
• Blower Motor Fuses: The HVAC blower motor draws significant current, especially on higher settings. If your fan isn't working, check the relevant fuses in both the under-hood and interior fuse boxes.
• Auxiliary Power / Upfitter Fuses: Many International LTs are upfitted with various auxiliary equipment. If any of these add-ons stop working, check the specific fuses dedicated to those circuits, often found in the interior fuse panel or the battery box fuse panel.

What to check first: Before suspecting a blown fuse, always consider if you've recently plugged in a new accessory or if a new piece of equipment was installed. Inspect the wiring for any obvious damage or signs of a short circuit, particularly around the component that has stopped working.

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