High Voltage Battery Disconnect Pyrofuse for Tesla Model 3/Y (1064689)

• HV Insulated Tool Set (Tesla Part No. 1057602-00-A, mandatory)
• T30 Torx screwdriver/bit (insulated)
• 13mm Insulated Socket & Torque Wrench (set to 9 Nm)
• HV Insulated Multimeter (to measure voltage)
• High-Voltage PPE (insulated gloves, goggles, boots)
• New M8 Bolts (2 pcs, one-time use, mandatory replacement)
• Tesla Toolbox 3 (for system calibration)

1. Place the vehicle in "Service Mode" via the touchscreen. Park on a flat surface, lift the vehicle to 50cm height with a jack and safety stands.
2. Disconnect the 12V battery negative terminal. Wait 5 minutes to allow the high-voltage capacitors to discharge completely.
3. Use an HV insulated multimeter to measure the busbar voltage — ensure it is less than 12V before proceeding.
4. Remove the HV battery compartment cover: Use an insulated T30 Torx tool to remove 8 bolts (diagonal order) and gently lift the cover, taking care not to damage the underlying wiring.
5. Locate the pyro disconnect (right side of the auxiliary compartment). Disconnect the electrical connector: press the lock tab and pull it horizontally to separate.
6. Remove the old pyro disconnect: Use an insulated 13mm socket to remove the 2 M8 bolts (9 Nm torque). Discard the old bolts (one-time use). Grip the unit firmly and pull it vertically upward to detach from the busbars.
7. Prepare the new unit (1064689): Wipe the busbar surface with an insulated cloth to remove dust and oxidation. Check the new unit’s terminals for damage; confirm the white installation arrow points toward the rear of the vehicle.
8. Install the new pyro disconnect: Align the unit’s locating pins with the busbar grooves, press it vertically downward until fully seated. Install the new M8 bolts and tighten to 9 Nm torque (diagonal order).
9. Reconnect the electrical connector: Push it horizontally until the lock tab clicks into place. Gently pull to confirm it is secure.

• MANDATORY HV INSULATED TOOLS — Non-insulated tools will cause electric shock, risking death or serious injury. Use Tesla-recommended HV Insulated Tool Set (Part No. 1057602-00-A).
• WAIT 5 MINUTES AFTER DISCONNECTING 12V BATTERY — Un discharged high-voltage capacitors will cause fatal electric shock. Do not skip this step.
• INSTALLATION ARROW MUST FACE REARWARD — Incorrect direction will disable the HV circuit, preventing the vehicle from starting and risking safety hazards.
• NEW M8 BOLTS ONLY — Old bolts are one-time use; reusing them risks loosening, high-voltage arcing, and fire.
• BUSBAR VOLTAGE MUST BE <12V — Never proceed with installation if voltage exceeds 12V; this indicates un discharged capacitors.
• SYSTEM CALIBRATION IS MANDATORY — Skipping calibration will trigger an HV system fault, and the vehicle will not operate.
• PROFESSIONAL INSTALLATION ONLY — Untrained personnel must not attempt to install this high-voltage component.
• DO NOT TOUCH BUSBARS/TERMINALS — Residual voltage may exist even after discharge; contact will cause electric shock.

10. Reconnect the 12V battery negative terminal. Use Tesla Toolbox 3 to calibrate the system and clear any fault codes.
11. Test the system: Start the vehicle, check for "HV System Normal" on the center display. Conduct a road test to ensure no fault codes appear.

Important Warnings

• ✅ Mandatory HV Insulated Tools — Non-insulated tools will cause electric shock, risking death or serious injury.
• ✅ Wait 5 minutes after disconnecting 12V battery — Un discharged capacitors will cause electric shock.
• ✅ Installation arrow must face rearward — Incorrect direction will disable the HV circuit and prevent the vehicle from starting.
• ✅ New M8 bolts only — Reusing old bolts risks loosening and high-voltage arcing.
• ✅ Busbar voltage must be <12V — Never operate if voltage is higher.
• ✅ System calibration is mandatory — No calibration = HV system fault, vehicle cannot run.
• ✅ Professional installation only — This is a high-voltage component; untrained personnel must not attempt installation.
• ✅ Do not touch busbars or terminals — Even after discharge, residual voltage may exist.