2003 Ford F-150 Fuse Box Diagram: Every Fuse, Both Boxes, Full Charts

Your 2003 F-150 has two fuse boxes. The passenger compartment fuse panel sits below and to the left of the steering wheel, next to the brake pedal, behind a cover. The power distribution box is in the engine compartment on the left side. The cigar lighter is fuse 3, rated 20A, in the cab panel.

Where are the fuse boxes on a 2003 F-150?

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Both boxes matter on this truck, which is not true of every F-150 generation.

Passenger compartment fuse panel. Below and to the left of the steering wheel, by the brake pedal, behind a removable cover. Driver side. This holds fuses 1 to 31 plus five relays.

Power distribution box. Engine compartment, left side. This one is a full fuse box, not a token relay holder. It carries mini fuses 1 to 23, the high current cartridge fuses 101 to 118, thirteen relays, two diodes and a circuit breaker.

If you own both a 2003 and a newer F-150, do not assume anything transfers. On a 2004 to 2008 truck the cab panel moved to the right side of the instrument panel, and the engine bay box shrank to a small auxiliary relay box. Same nameplate, different truck.

2003 F-150 passenger compartment fuse chart

Driver side, by the brake pedal. All mini fuses.

Relays in this panel: R1 interior lamp, R2 battery saver, R4 one-touch down window, R5 accessory delay. R3 is not used.

Assignments vary with trim and options. Your truck may not use every position listed.

2003 F-150 power distribution box chart

Engine compartment, left side. Mini fuses first.

High current cartridge fuses in the same box:

Position 102 is the one place my sources split. One lists 50A, another 20A. The rating depends on whether your truck has four wheel or rear wheel anti-lock brakes. Read the number off the fuse you pull, and match it.

Position 601 is a resettable circuit breaker, not a fuse. If your windows died and came back on their own a minute later, that breaker tripped and reset. Look for a binding window or a tired motor.

Which fuse is the cigar lighter and 12V power point?

On a 2003 F-150 the cigar lighter is fuse 3, rated 20A, in the passenger compartment panel. It shares that circuit with the data link connector, which is why a blown fuse 3 can also stop a scan tool from connecting.

The other power points live in the engine bay box: fuse 1, 20A for the main power point, fuse 12, 20A for the rear auxiliary point on SuperCrew, and fuse 4, 20A for the console point on Harley-Davidson trucks.

Here is where nearly every fuse chart online will send you wrong, and it happens twice.

Trap one, the rating changed inside the same generation.

The position stayed at 3 for the whole 1997 to 2003 run, but Ford dropped the rating. Fitting a 25A fuse in a 2003 truck because a 1998 chart said so puts 5A more current through wiring sized for 20A.

Trap two, the position changed completely in 2004.

If you searched “F-150 cigar lighter fuse” and landed on a chart showing fuse 41, you were reading about a truck built at least a year after yours. Our 2006 Ford F-150 fuse box diagram covers that layout properly.

The label printed inside your own fuse box cover is the final authority. Trim, market and mid-year production changes all move things, and that cover was printed for your specific truck.

Which fuse controls the radio?

Three separate fuses feed the audio system, and which one you lost tells you what to expect.

• Fuse 1, 15A: audio. Main feed. Blow this and the radio is dead.
• Fuse 8, 5A: radio, remote entry module, GEM. Also feeds the in-vehicle entertainment system on SuperCrew.
• Fuse 20, 5A: audio, GEM, PCM, transmission range sensor. Shared with powertrain circuits, so a fault here rarely presents as audio alone.
• Power distribution box fuse 117, 40A: Audiophile radio, SuperCrew only. Premium system with the amplifier.

Fuse 30 also touches the radio through the radio noise capacitor, but it is primarily the ignition coil and anti-theft circuit. If fuse 30 is blown your truck will not start, and the silent radio is the smaller of your problems.

Which fuse controls the A/C, blower and heated seats?

Comfort circuits split across both boxes, so the symptom tells you which box to open.

The blower is the one people get wrong most. It is a 40A cartridge fuse in the engine bay, not a mini fuse in the cab. If the fan works on high but nothing else, the fuse is fine and you are looking at a blower motor resistor instead.

Which fuse stops the truck from starting?

Four positions can leave you turning the key with nothing happening.

1. Fuse 30, 30A, cab panel. Ignition coils, PCM relay, coil on plugs, and the passive anti-theft transceiver. The broadest no-start fuse on the truck. If the theft light behaves oddly alongside the no-start, read our Ford PATS system reset guide before you buy parts.
2. Fuse 21, 15A, cab panel. DTR sensor, clutch switch, starter relay.
3. Fuse 111, 40A, engine bay. Ignition switch battery feed, start and run circuits.
4. Fuse 10, 20A, engine bay. Fuel pump. Engine cranks but will not fire.

Cranks but will not start points at fuel or spark, so check 10 and 30. No crank at all points at 21 or 111.

How do you tell if a fuse is actually blown?

Pull it and look through the plastic window at the metal strip. An intact fuse has an unbroken S-shaped element. A blown one shows a visible gap, or the window is smoked brown or black.

Three things catch people out on this truck:

1. A hairline break looks intact. Hold the fuse to a light. If you are not certain, test continuity with a multimeter set to ohms. Near zero means good.
2. Never guess the replacement rating. Match the number printed on the fuse and cross-check the box cover label. Fitting 30A where 10A belongs lets the wiring become the fuse.
3. The cartridge fuses need a puller. Positions 101 to 118 are the flat cartridge type. Pliers crack the housing. A mixed ATO/ATC fuse assortment kit costs less than one dealer fuse and usually includes the puller.

Why does the same fuse keep blowing?

A fuse that blows once is usually a surge. One that blows again within days is telling you the fault is upstream, and replacing it repeatedly treats the alarm instead of the fire.

Work through it in this order:

1. Unplug whatever you added most recently. Trailer wiring, a dash cam, an aftermarket stereo, a charger left in the 12V socket. Aftermarket accessories cause most repeat blows on these trucks.
2. Check where the harness moves. Door jambs, the tailgate run, and anything near the steering column flex thousands of times and chafe.
3. Look for water. A wet connector shorts intermittently, which is why the fuse survives a dry week and dies in the rain.
4. Consider the load. A binding window keeps tripping breaker 601. A failing blower keeps taking out fuse 105.

Two circuits on this truck have their own habits worth knowing. Fuse 23 feeds the 4×4 solenoids and relays, so if it keeps blowing and the transfer case is slow to engage, see 4×4 actuator problems. Fuse 101 and 108 feed trailer charging and electric brakes, and a corroded seven-pin connector is the usual culprit, covered in our trailer brake module fault guide.

If a fuse blows the instant you seat it, there is a hard short. Stop replacing fuses and trace the circuit. A Ford-capable scan tool will read the live data you need rather than guessing.

2003 F-150 fuse quick reference

The positions owners look up most, in one place. C means the cab panel, E means the engine bay box.

If your truck is a different year, our F-150 fuse box identification guide covers how the panels differ across generations, and there is a dedicated 2000 F-150 under-dash fuse box page for the earlier layout.