2018 Toyota Highlander Fuse Box Diagram & Amperage
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Quick answer
The 2018 Toyota Highlander has three main fuse box locations: under the hood (engine compartment), under the dashboard (driver's side kick panel), and in the cargo area (rear of the vehicle).
Under-Hood Fuse Box
The under-hood fuse box, located in the engine compartment on the driver's side, contains fuses for critical engine functions, headlights, and other high-current components. This box also houses several relays.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| EFI NO.1 | 10A | Red | ECM/PCM, Fuel Pump, Ignition |
| EFI NO.2 | 15A | Blue | Fuel Injectors, ECM/PCM |
| H-LP LH | 10A | Red | Left Headlight (Low Beam) |
| H-LP RH | 10A | Red | Right Headlight (Low Beam) |
| H-LP HI LH | 10A | Red | Left Headlight (High Beam) |
| H-LP HI RH | 10A | Red | Right Headlight (High Beam) |
| HORN | 10A | Red | Horn |
| ABS NO.1 | 30A | Green | ABS Pump Motor |
| ABS NO.2 | 20A | Yellow | ABS Solenoids |
| A/C MAG | 10A | Red | A/C Compressor Clutch |
| AM2 | 15A | Blue | Ignition Switch, Starter Relay |
| IGN | 10A | Red | Ignition System |
| STARTER | 50A | Red | Starter Motor |
| TOWING B/U | 30A | Green | Trailer Brake Controller (if equipped) |
| TOWING TL | 20A | Yellow | Trailer Tail Lights (if equipped) |
Relays located in the under-hood fuse box often include:
- EFI Relay: Controls power to the EFI system, including the fuel pump.
- Horn Relay: Activates the horn.
- Headlight Relays: Control power to the headlights (separate relays for low and high beams).
- A/C Mag Clutch Relay: Engages the A/C compressor clutch.
- Starter Relay: Engages the starter motor.
Driver's Side Kick Panel Fuse Box
This fuse box is located on the driver's side, behind a cover in the kick panel area. It primarily protects interior electrical components and accessories.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| CIG | 15A | Blue | Cigar Lighter, 12V Power Outlet |
| P/OUTLET | 15A | Blue | Additional 12V Power Outlet |
| RADIO | 10A | Red | Radio, Infotainment System |
| WIPER | 20A | Yellow | Windshield Wipers |
| WASHER | 15A | Blue | Windshield Washer Pump |
| MIRROR | 10A | Red | Power Mirrors |
| DOOR | 20A | Yellow | Power Windows, Door Locks |
| A/BAG NO.1 | 10A | Red | Airbag System (SRS) |
| STOP | 10A | Red | Brake Lights, Cruise Control |
| TAIL | 10A | Red | Tail Lights, Parking Lights |
| DOME | 10A | Red | Interior Lights |
| HEATER | 40A | Green | Blower Motor (Heater/AC) |
| BLOWER | 30A | Green | Blower Motor (Heater/AC) * |
*Note: Some Highlander trims may have a separate "HEATER" or "BLOWER" fuse. Always verify with your vehicle's specific fuse box legend.
Cargo Area Fuse Box
Located in the rear of the vehicle, often on the driver's side panel behind a removable cover, this fuse box handles power for rear accessories and features.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| P/OUTLET RR | 15A | Blue | Rear 12V Power Outlet |
| TOWING B/U RR | 30A | Green | Trailer Brake (Rear, if equipped) |
| TOWING TAIL RR | 20A | Yellow | Trailer Tail/Park Lights (Rear, if equipped) |
| RR WIPER | 15A | Blue | Rear Wiper |
| RR WASHER | 15A | Blue | Rear Washer Pump |
How to test a fuse
Testing a fuse is a straightforward process and requires a fuse puller (usually found in the fuse box lid) and a multimeter or a fuse tester. Always ensure the vehicle
Before you pull a fuse on the 2018 Toyota Highlander
- Use the label printed on the panel cover or the owner's manual for your exact build. Layouts change with options, model year and build date, so a chart for another truck can be wrong.
- Replace a blown fuse only with the same amp rating. A larger fuse can let wiring overheat.
- A fuse that blows again right away means a short or failing component downstream. Find the cause before replacing it again.
- A good fuse doesn't prove the circuit works — relays, grounds and connectors fail too.
- Disconnect the battery before working near high-current fuses or cables.
Learn more: How fuses, relays and truck electrical systems work
More specs for the 2018 Toyota Highlander
Oil Capacity & Filter
Capacity, weight, filter PN, drain plug torque, change interval.
Fluid Type Specs
Engine oil, coolant, ATF, diff, brake, PS, DEF — with OEM spec numbers.
Coolant Capacity & Type
Total system capacity, OEM coolant spec, flush interval, bleed tips.
Transmission Fluid & Service
Trans model, fluid spec, capacity, filter PN, service interval.
Torque Specifications
Lug nuts, drain plug, caliper, axle nut, plug, key fasteners.
Brake Pad & Rotor Specs
Pad PNs, rotor size, min thickness, caliper torque.
Tire Size & Pressure
OEM size, cold psi, bolt pattern, wheel size, TPMS.
Battery Size & Group
Group size, CCA, AGM/flooded, dimensions, reset note.
A/C Refrigerant & Oil
R-134a or R-1234yf, charge oz, PAG oil spec.
Bulb Sizes (Headlight, Tail, Fog)
Headlight, fog, tail, turn, reverse, interior.
Factory Maintenance Schedule
Service intervals by mileage, severe-duty notes, known issues.
Towing Capacity & Payload
Max tow, payload, GVWR/GCWR, hitch class by trim.
Serpentine Belt Routing & Length
Belt routing, length, rib count, OEM + aftermarket PNs.
Wheel Alignment Specifications
Camber, caster, toe ranges (front & rear), adjustability notes.
Paint Color Codes
All factory colors with paint codes, sticker location, touch-up tips.
Wiper Blade Sizes
Driver/passenger/rear blade size, attachment, OEM + cross-refs.
Spark Plug Type & Gap
Plug PN, gap, torque, interval by engine.
Transmission & Axle Gear Ratios
Trans gear ratios, axle ratios, RPO codes, tow vs MPG impact.
Key Fob Programming
DIY programming steps, FCC ID, fob PN, battery, transponder.
Same spec — other model years
Maintenance & repair guides
2018 Toyota Highlander Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
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