Toyota 4Runner 2003 Fuse Replacement
Having an electrical issue? It could be a blown fuse — an easy fix you can do yourself.
Follow the steps below to find and replace the fuse:
Step 1: Find the Fuse Box
In your Toyota 4Runner 2003, the interior fuse box is typically located under the dashboard on the driver's side. Some vehicles also have an additional fuse box in the engine compartment. Check your owner's manual or the fuse box cover for the exact location.
Step 2: Identify the Corresponding Fuse
Below is the complete fuse list for your vehicle. Find the circuit that isn't working and note the fuse number and amperage.
Passenger Compartment Fuse Box
| Fuse # | Function | Amperage |
|---|---|---|
| 1 | IGN | 10 |
| 2 | SRS | 10 |
| 3 | GAUGE | 7.5 |
| 4 | STA NO.2 | 7.5 |
| 5 | FR WIP-WSH | 30 |
| 6 | Spare | |
| 7 | 4WD | 20 |
| 8 | Spare | |
| 9 | Spare | |
| 10 | D P/SEAT | 30 |
| 11 | P P/SEAT | 30 |
| 12 | PWR OUTLET | 15 |
| 13 | Spare | |
| 14 | RR WSH | 15 |
| 15 | ECU-IG | 10 |
| 16 | IG1 | 15 |
| 17 | STA | 7.5 |
| 18 | SECU/HORN | 10 |
| 19 | Spare | |
| 20 | Spare | |
| 21 | Spare | |
| 22 | TAIL | 10 |
| 23 | ACC | 7.5 |
| 24 | CIG | 10 |
| 25 | POWER | 30 |
| Relay | Spare | |
| R1 | Spare | |
| R2 | Spare | |
| R3 | Spare | |
| R4 | Spare |
Engine Compartment Fuse Box
| Fuse # | Function | Amperage |
|---|---|---|
| 1 | SPARE | 10 |
| 2 | SPARE | 15 |
| 3 | Spare | |
| 4 | Spare | |
| 5 | Spare | |
| 6 | STOP | 10 |
| 7 | AC115V INV | 15 |
| 8 | FR FOG | 15 |
| 9 | Spare | |
| 10 | OBD | 7.5 |
| 11 | HEAD (LO RH) | 10 |
| 12 | HEAD (LO LH) | 10 |
| 13 | HEAD (HI RH) | 10 |
| 14 | HEAD (HI LH) | 10 |
| 15 | EFI NO.2 | 10 |
| 16 | HEATER NO.2 | 7.5 |
| 17 | AIRSUS NO.2 | 10 |
| 18 | SEAT HEATER | 25 |
| 19 | DEFOG | 30 |
| 20 | MIR HEATER | 10 |
| 21 | DOME | 10 |
| 22 | RADIO NO.1 | 20 |
| 23 | ECU-B | 10 |
| 24 | Spare | |
| 25 | Spare | |
| 26 | ALT-S | 7.5 |
| 27 | Spare | |
| 28 | HORN | 10 |
| 29 | A/F HEATER | 15 |
| 30 | TRN-HAZ | 15 |
| 31 | ETCS | 10 |
| 32 | EFI | 20 |
| 33 | Spare | |
| 34 | DR/LCK | 20 |
| 35 | TOWING | 30 |
| 36 | RADIO NO.2 | 20 |
| 37 | ALT | 140 |
| 38 | A/PUMP | 50 |
| 38 | HEATER | 50 |
| 39 | AIRSUS | 50 |
| 40 | AM1 | 50 |
| 41 | TOWING BRK | 30 |
| 42 | J/B | 50 |
| 43 | BATT CHG | 30 |
| 44 | TOWING | 40 |
| 45 | ABS MTR | 40 |
| 46 | AM2 | 30 |
| 47 | ABS SOL | 50 |
| 47 | ABS SOL | 30 |
| 48 | HEATER | 60 |
| Relay | Spare | |
| R1 | Spare | |
| R2 | Spare | |
| R3 | Spare | |
| R4 | Spare | |
| R5 | Spare | |
| R6 | Spare | |
| R7 | Spare | |
| R8 | Spare | |
| R9 | Spare | |
| R10 | Spare | |
| R11 | Spare | |
| R12 | Spare | |
| R13 | Spare | |
| R14 | Spare | |
| R15 | Spare | |
| R16 | Spare | |
| R17 | Spare | |
| R18 | Spare | |
| R19 | Spare |
Step 3: Check the Fuse
Use the plastic fuse puller, typically found in the fuse box, to remove the fuse. Hold it up to a light source. If the metal filament inside is broken or charred, the fuse is bad and needs to be replaced.
Step 4: How to Get a Replacement
You can buy a replacement fuse at any auto parts store. Make sure you match the **amperage (A)** and **physical size** of the fuse exactly. For example, if you need a 20A fuse, get a 20A fuse.
Step 5: Replace the Fuse
Gently press the new fuse into the empty slot. You should feel a slight click when it's securely in place. Test the affected circuit to confirm it's working again.
What Now?
Fuse Was Blown — What to Buy
Ask at any auto parts store (AutoZone, O'Reilly, Advance Auto) for a blade fuse with the same amperage printed on the old one (e.g., 10A, 15A, 20A). Also match the physical size — mini (most modern cars), standard, or maxi. Replacement fuses cost under $5 and most stores sell assorted packs.
Fuse Looks Fine — Other Causes
If the fuse is intact, the problem isn't a blown fuse. Common alternatives include a bad relay (a click-sized electrical switch), a faulty wiring connection, or a failed component (motor, switch, module). At this point, a mechanic's diagnostic is the most reliable next step.
Frequently Asked Questions
What happens if I put in the wrong amperage fuse?
Higher amperage fuses won't protect the circuit and can cause wiring damage or fire. Lower amperage fuses will blow again immediately. Always match the exact amperage.
Why does my fuse keep blowing?
A repeatedly blown fuse indicates an underlying short circuit or overload. Replacing it again won't fix the root cause — consult a mechanic.
Do I need any tools?
Most cars come with a plastic fuse puller in the fuse box lid. If not, fine-tip needle-nose pliers work. A small flashlight helps.
How do I know what size fuse to buy?
Match the amperage printed on the old fuse (e.g., 10A, 15A, 20A) and the physical blade size (mini, standard, maxi). Auto parts stores carry assorted packs.