2021 Nissan Altima Fuse Box Diagram & Amperage
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Quick Answer
The 2021 Nissan Altima has three main fuse box locations: under the hood, behind the driver's side kick panel (interior), and in the trunk/cargo area.
Under-Hood Fuse Box
This fuse box is located in the engine compartment, typically near the battery. It houses fuses and relays for critical engine functions, lighting, and major electrical components. Always consult your owner's manual and the fuse box lid for the most accurate diagram for your specific trim level, as configurations can vary.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| 1 | 15A | Blue | ECM (Engine Control Module) |
| 2 | 10A | Red | Ignition Coils / Spark Plugs |
| 3 | 15A | Blue | Fuel Pump |
| 4 | 30A | Green | ABS (Anti-lock Brake System) SOL |
| 5 | 40A | Green | ABS (Anti-lock Brake System) MTR |
| 6 | 15A | Blue | Headlight (Low Beam, Right) |
| 7 | 15A | Blue | Headlight (Low Beam, Left) |
| 8 | 10A | Red | Headlight (High Beam, Right) |
| 9 | 10A | Red | Headlight (High Beam, Left) |
| 10 | 10A | Red | Starter Relay Coil |
| 11 | 20A | Yellow | Blower Motor |
| 12 | 10A | Red | A/C Clutch |
| 13 | 15A | Blue | Horn |
| 14 | 10A | Red | Tail Lights / Parking Lights |
| 15 | 10A | Red | Brake Lights (Stop Lamps) |
| 16 | 15A | Blue | Power Steering |
| 17 | 10A | Red | Fog Lights |
| 18 | 20A | Yellow | Washer Pump |
| 19 | 15A | Blue | Wiper Motor |
| 20 | 10A | Red | O2 Sensor |
Common Relays in the Under-Hood Fuse Box:
- 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, sometimes integrated or combined.
- A/C Compressor Relay: Activates the A/C clutch.
- Horn Relay: Controls the vehicle
Before you pull a fuse on the 2021 Nissan Altima
- 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 2021 Nissan Altima
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
2021 Nissan Altima 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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