Install an aftermarket subwoofer system in the trunk area, including wiring from the battery through the cabin to the amplifier and subwoofer enclosure.

Warnings

Tools required

Parts

• Subwoofer enclosure with speaker × 1 — Aftermarket - sized for trunk
• Amplifier × 1 — Aftermarket - match to subwoofer specs
• Power wire kit (4-8 AWG) × 1 — Include fuse holder and inline fuse
• Ground wire (4-8 AWG) × 1 — Match power wire gauge
• RCA cables × 1 — Shielded, appropriate length
• Remote turn-on wire (18 AWG) × 1 — Blue wire standard
• Speaker wire × 1 — 12-16 AWG, appropriate length
• Ring terminals × 3 — Match wire gauge
• Inline fuse holder with fuse × 1 — Match amplifier requirements
• Grommets for firewall pass-through × 1 — Appropriate for wire gauge

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery terminal and wait 90 seconds
3. Remove trunk floor mat and spare tire cover to access trunk area
4. Plan wire routing path from battery through firewall to trunk, avoiding moving parts and heat sources
5. Identify existing firewall grommet on driver side for wire pass-through

Procedure

1. 1

   Install inline fuse holder at battery
   Connect inline fuse holder to positive battery terminal using appropriate ring terminal. Position fuse holder within 18 inches of battery. Insert fuse rated for amplifier draw (typically 40-80A). Do not fully tighten terminal bolt yet - just hand tight for now.
2. 2

   Route power wire through firewall
   Locate existing firewall grommet on driver side near fuse box area. Carefully create small slit in grommet or use existing pass-through. Use fish tape to route power wire from engine bay through firewall into cabin. Install protective grommet around wire at firewall penetration point. Ensure wire does not contact hot or moving engine components.
3. 3

   Route power wire through cabin
   Remove driver side door sill trim panel using trim tools. Route power wire under carpet along driver side, then cross under rear seat to trunk area. Secure wire with zip ties to existing wiring harnesses where possible. Keep wire away from seat tracks and moving parts. Reinstall door sill trim.
4. 4

   Route RCA and remote wire
   Connect RCA cables and remote turn-on wire to head unit speaker outputs or line-out converter if needed. Route these signal wires along passenger side of vehicle (opposite power wire to reduce interference). Use same method as power wire routing - under carpet and trim. Route to trunk area.
5. 5

   Position and secure amplifier
   Choose amplifier mounting location in trunk (typically driver side wall or under rear deck). Ensure adequate ventilation around amplifier. If using mounting bolts through trunk floor or wall, verify no fuel lines, brake lines, or wiring behind mounting area. Secure amplifier using appropriate mounting hardware. If bolting to metal, torque mounting bolts appropriately.
   Torque spec

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

   Establish amplifier ground connection
   Locate bare metal grounding point on vehicle chassis within 18 inches of amplifier (typically trunk floor bolt or dedicated ground point). Remove paint or coating using sandpaper or wire brush to expose bare metal. Attach ground wire ring terminal to ground point. Clean contact surfaces thoroughly before connection.
   ⚠Ground connection quality is critical for system performance and safety. Ensure metal-to-metal contact with no paint, rust, or coating between surfaces.
   Torque spec

   Ground Bolt13 Nm (10 lb-ft)
7. 7

   Connect power wire to amplifier
   Route power wire from cabin to amplifier location. Trim to appropriate length leaving 6 inches extra. Strip wire end and connect to amplifier power terminal. Ensure connection is tight and secure. Verify no exposed wire strands that could cause short circuit.
8. 8

   Connect signal wires to amplifier
   Connect RCA cables to amplifier RCA inputs matching left/right channels. Connect remote turn-on wire to amplifier remote terminal (typically blue wire). Ensure all connections are secure. Route excess wire neatly and secure with zip ties.
9. 9

   Position subwoofer enclosure
   Place subwoofer enclosure in desired trunk location. For best performance, position against rear seat back or in corner. Ensure enclosure does not interfere with trunk closing or spare tire access if needed. Secure enclosure to prevent movement during driving using mounting bolts, straps, or Velcro depending on installation preference.
10. 10

    Connect speaker wire to subwoofer
    Run speaker wire from amplifier speaker outputs to subwoofer terminals. Observe correct polarity (positive to positive, negative to negative). Strip wire ends and connect securely to both amplifier and subwoofer terminals. Keep speaker wire away from power wire to reduce potential interference.
11. 11

    Reconnect battery and test system
    Return to battery and securely connect power wire ring terminal to positive battery terminal. Torque battery terminal bolt to specification. Reconnect negative battery terminal and torque to specification. Turn ignition to ACC position and power on head unit. Verify amplifier powers on (check power LED). Test subwoofer output at low volume initially.
    ⚠Do not exceed specified torque on battery terminals as this can damage terminal posts or clamps.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)
12. 12

    Adjust amplifier settings
    Set amplifier gain control to minimum. Adjust crossover frequency to match subwoofer specifications (typically 80Hz for sealed enclosure). Set bass boost to zero initially. Slowly increase gain while playing familiar music until desired output is achieved without distortion. Fine-tune crossover and phase settings for best integration with factory speakers.

Reassembly

1. Verify all trim panels and door sills are properly reinstalled and secured
2. Ensure all wiring is secured with zip ties and protected with wire loom where exposed
3. Reinstall trunk floor mat and spare tire cover
4. Check that trunk closes properly and subwoofer enclosure does not interfere with operation

Verification

• With engine off and ignition in ACC, verify amplifier powers on when head unit is turned on
• Play music with bass content and verify subwoofer produces sound without distortion at moderate volume
• Check that subwoofer stops when head unit is turned off (remote wire functioning)
• Inspect all wire routing to ensure nothing is pinched, exposed to heat, or able to contact moving parts
• Verify battery terminals are secure and show no signs of arcing or poor connection
• Test system at various volume levels to confirm no rattling, buzzing, or distortion
• Use multimeter to verify amplifier is receiving proper voltage (should be 12-14V with engine running)

More procedures for this vehicle