2021 Tesla Model S — Fuse Box Diagram & Amperage

Quick answer

• Front trunk (under-hood) service fuse block: Right side of the frunk under the cowl trim. Houses the primary low‑voltage (12V) serviceable mini fuses for exterior lighting, horn, wipers/washer, HVAC blower, accessory power, SRS/airbag supply, ABS supply, coolant pumps, and select control modules.
• Passenger dash/kick‑panel fuse block (if equipped on your build): Behind the right‑side lower dash or kick‑panel trim. Feeds interior power such as 12V outlet, USB hubs, infotainment/MCU, interior lamps, power seats/windows, and OBD‑II.
• Rear trunk right‑side fuse/relay module (if equipped): Behind the right‑rear quarter trim in the cargo area. Supports rear defroster, power liftgate, charge‑port actuator/lighting, air‑suspension compressor/valves (if equipped), and tail/park circuits.
• High‑voltage battery pyrofuse and contactors (not user‑serviceable): Within the traction battery assembly—crash isolation and main HV switching; no conventional fuses to service.

Note: Tesla migrated many circuits to solid‑state electronic protection. Numbers and ratings vary by build year/month and options. Never rely on a generic chart alone—verify the exact fuse number, color, and rating printed on your vehicle’s fuse box lid/legend.

Front trunk (under‑hood) service fuse block

Location: Open the frunk and remove the right‑side plastic cowl/trim panel to access the low‑voltage fuse block.

Relays in this area: Most relay functions (lighting, wipers, HVAC, pumps) are solid‑state inside the body controller; you will not see conventional plug‑in relays here.

Notes:

• Many lighting and body functions are protected and switched by the body controller with electronic fusing; blown “fuses” may be internal and require service tools to diagnose. Always confirm the exact cavity and rating on your lid legend.

Passenger dash / right kick‑panel fuse block (if equipped)

Location: Right‑side lower dash. Remove the side trim or kick‑panel to reveal the interior fuse access (present on some 2021 builds; others route these circuits to the front block).

Relays in this area: None typical; relay logic handled in the body/Gateway controller.

Notes:

• ECM/PCM, fuel pump, ignition, and starter relay are not applicable on this EV. Drive inverters and HV contactors are managed by the battery and vehicle controllers and are not protected by user‑serviceable fuses.

Rear trunk right‑side fuse/relay module (if equipped)

Location: Behind the right‑rear trunk side trim panel. Remove the cargo floor and right‑side trim to access.

Relays in this area: Air‑suspension valve block and compressor control are solid‑state/within modules. Liftgate and rear defroster switching typically solid‑state.

How to test a fuse

1. Make it safe: Power the car down on the screen when possible and open a door to keep it awake. Turn off accessories and chargers. Do not open the HV battery or orange‑cable components.
2. Access and identify: Remove the applicable trim to reach the fuse block. Use the legend on the lid to identify the suspected cavity.
3. Visual check: Use the fuse puller to remove the mini fuse. Look for a melted or broken metal link.
4. Meter test: With a digital multimeter in continuity or ohms mode, probe both blades—good fuses read near 0 Ω. Alternatively, with the circuit powered, use a test light on the exposed test tabs on top of the fuse; both tabs should light on a good fuse.
5. Replace exactly: Install a fuse of the same amp rating and body size/color. Never up‑size to stop a recurring blow—find and fix the root cause.
6. Recheck operation: Verify the component works and that no warnings appear. If the new fuse blows immediately, stop and diagnose the circuit for shorts, water intrusion, or a failed component.

Common blown fuses on this vehicle (what to check first)

• 12V accessory outlet: Often pops due to high‑draw phone/laptop chargers or coin/debris in the socket. Inspect the socket for shorts and try a known‑good charger before replacing the fuse.
• USB hubs/wireless charger: Aftermarket cables or devices can overload the port. Unplug everything and retest after replacing the fuse.
• Washer pump: Frozen fluid or a seized pump can over‑current. Verify fluid type for your climate and check the pump at the frunk reservoir area for leaks or binding.
• Wipers: Binding linkages or iced blades can stall the motor. Free the blades and check the cowl drains for debris; a stalled motor will re‑blow the fuse.
• Horn: Water intrusion into the horn or front harness causes repeat failures. Inspect connectors and sound the horn briefly with a meter in line if needed.
• Rear defroster: High resistance at the glass tabs or broken grid can overheat the circuit. Inspect the grid and tab solder joints.
• Air‑suspension (if equipped): Compressor over‑current from clogged dryer or leaks. Listen for frequent running and perform a bubble test on lines/bags; repeated fuse failure points to compressor or relay driver faults.

Important Tesla specifics:

• Many body and powertrain protections are electronic and self‑resetting. If a function is inoperative without a blown service fuse, check the car’s alerts/notifications and perform a soft reboot. Persistent faults may require Tesla‑specific diagnostics.
• There is no ECM/PCM, fuel pump, ignition, or starter relay fuse as in gasoline vehicles. Drive enable is controlled by the HV battery, contactors, and inverters—do not service these without proper training.

Always confirm fuse cavity numbers and exact ratings on the printed legend inside your fuse‑box lid; Tesla revised layouts across 2021 refresh builds and option packages.

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