Installation of an aftermarket subwoofer in the trunk of a 2012-2017 Toyota Camry, including wiring from the head unit and power connection from the battery.

Warnings

Tools required

Parts

• Subwoofer × 1 — Aftermarket component
• Subwoofer amplifier × 1 — Aftermarket component
• Amplifier wiring kit (4-8 gauge) × 1 — Include power wire, ground wire, RCA cables, remote wire, fuse holder
• Subwoofer enclosure × 1 — Aftermarket component
• Speaker wire (for subwoofer to amp) × 1 — 12-16 gauge
• Ring terminals × 3 — Appropriate for wire gauge used
• Inline fuse holder and fuse × 1 — Rated for amplifier current draw

Preparation

1. Park vehicle on level ground and engage parking brake
2. Disconnect negative battery terminal using 10mm wrench and secure away from battery post
3. Wait 90 seconds for airbag system to discharge
4. Plan wire routing path from battery through firewall grommet (passenger side) to trunk, avoiding hot engine components and moving parts
5. Determine subwoofer and amplifier mounting locations in trunk
6. Verify amplifier power requirements and ensure wiring kit gauge is appropriate

Procedure

1. 1

   Remove trunk trim panels
   Open trunk and remove necessary trim panels on driver side to access wire routing path. Use trim tools to carefully pry side panel clips starting from bottom. Remove any cargo hooks or fasteners. Set panels and clips aside in organized manner for reinstallation.
2. 2

   Route power wire from battery to trunk
   Locate existing firewall grommet on passenger side near battery. Make small slit in grommet using blade, being careful not to damage existing wires. Feed power wire through grommet into cabin. Route wire under door sills by removing scuff plates (pull up firmly). Feed wire along passenger side under carpet edge to rear seat area. Remove lower rear seat cushion by pulling up firmly on front edge. Feed power wire from cabin into trunk through existing wire passage or create new protected passage.
3. 3

   Install inline fuse holder at battery
   Locate power wire at battery compartment. Install inline fuse holder within 18 inches of positive battery terminal. Do not insert fuse yet. Attach appropriate ring terminal to power wire end at battery. Ensure crimp connection is secure and insulated with heat shrink or electrical tape.
4. 4

   Mount amplifier in trunk
   Position amplifier in chosen trunk location (typically on side panel or behind rear seat). Ensure location allows adequate ventilation and does not interfere with spare tire or cargo. Mark mounting holes. If using existing threaded holes, verify thread size. If drilling new holes, ensure no fuel tank, fuel lines, or wiring behind mounting surface. Secure amplifier using appropriate hardware. If using factory mounting points, torque module mounting bolts to specification.
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
5. 5

   Connect amplifier ground wire
   Locate suitable grounding point within 18 inches of amplifier. Use existing factory ground bolt on chassis or body (typically on rear floor or wheel well). Remove ground bolt, clean contact surfaces of paint and rust using wire brush or sandpaper down to bare metal. Attach ring terminal on amplifier ground wire to ground bolt location. Reinstall bolt and torque to specification ensuring clean metal-to-metal contact.
   Torque spec

   Ground Bolt14 Nm (10 lb-ft)
6. 6

   Route RCA and remote turn-on cables
   Access head unit by removing radio trim panel (pull firmly from edges). Remove radio mounting bolts and pull unit forward to access rear connections. Connect RCA cables to head unit subwoofer outputs or rear outputs. Connect remote turn-on wire to head unit's remote/amp turn-on output (typically blue/white wire). Route RCA cables and remote wire along passenger side opposite from power wire, following same path under door sills and through to trunk. Keep signal cables at least 12 inches from power wire throughout run.
7. 7

   Position and secure subwoofer enclosure
   Place subwoofer enclosure in desired trunk location. Ensure enclosure does not interfere with trunk lid closure or block access to spare tire. Secure enclosure using mounting hardware, straps, or L-brackets to prevent movement during driving. If bolting down, verify no fuel tank or components behind drill locations. Measure and cut speaker wire to connect subwoofer terminals to amplifier output terminals.
8. 8

   Connect all amplifier wiring
   Connect power wire to amplifier positive terminal and torque terminal bolt to specification. Connect ground wire to amplifier ground terminal and torque terminal bolt to specification. Connect RCA cables to amplifier inputs (left/right or single mono input). Connect remote turn-on wire to amplifier remote terminal. Connect speaker wire from subwoofer to amplifier output terminals, observing correct polarity (positive to positive, negative to negative). Torque all terminal bolts to specification.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
9. 9

   Secure and protect all wiring
   Use zip ties to secure all wiring along routing path, attaching to existing wire harnesses or secured to body where appropriate. Ensure no wires can contact hot engine components, moving parts, or sharp edges. Add protective loom or tape at any points where wires pass through metal openings. Verify all wiring has appropriate slack and is not stretched tight. Tuck and secure wires under carpet edges and behind trim panels.
10. 10

    Connect battery and test system
    Verify all connections are tight and properly insulated. Insert fuse into inline fuse holder near battery. Reconnect negative battery terminal and torque battery terminal bolt to specification. Do not overtighten. Turn vehicle to ACC or ON position without starting engine. Power on head unit and verify amplifier powers on (check indicator light). Play audio with bass content and verify subwoofer operates correctly. Adjust amplifier gain, crossover, and bass boost settings as needed. Check for distortion, rattles, or overheating.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Reinstall all trim panels, ensuring all clips are fully seated
2. Reinstall rear seat cushion by aligning clips and pressing down firmly until locked
3. Reinstall door scuff plates
4. Reinstall radio trim panel and verify proper fit
5. Test trunk lid operation to ensure no interference with subwoofer enclosure
6. Verify all trunk functions including spare tire access remain unobstructed

Verification

• Turn ignition to ON position and verify amplifier powers on with head unit
• Play audio source with bass content and verify subwoofer produces sound
• Check for proper subwoofer response across volume range without distortion
• Verify no rattles from trunk panels or loose components
• Check amplifier does not overheat during extended use
• Confirm all electrical accessories and radio functions operate normally
• Test drive vehicle and verify subwoofer operates correctly and no wiring vibration noises present
• Verify no battery drain issues with vehicle off (amplifier should not draw power)

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