Install an aftermarket subwoofer in the 2011-2014 Ford F-150 crew cab or extended cab, including wiring from the amplifier and mounting in the rear cabin area.

Warnings

Tools required

Parts

• Aftermarket subwoofer with enclosure × 1 — Use desired aftermarket specification
• Amplifier wiring kit (4 or 8 gauge) × 1 — Use amplifier power requirements
• In-line fuse holder with appropriate fuse × 1 — Match to amplifier current draw
• RCA cable kit × 1 — Use quality shielded cables
• Speaker wire (12 or 14 gauge) × 1 — Sufficient length for routing
• Wire loom or conduit × 1 — For wire protection
• Zip ties × 10 — Assorted sizes

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery terminal and wait 10 minutes for airbag system capacitors to discharge
3. Plan wire routing from battery through firewall to amplifier location and from head unit to amplifier
4. Determine subwoofer mounting location in rear cabin (typically behind rear seat in crew cab or under rear seat in extended cab)
5. Verify amplifier installation location (common locations include under rear seat or behind rear seat)

Procedure

1. 1

   Remove rear seat (if applicable)
   For crew cab models, lift the rear seat bottom cushion by pulling upward firmly at the front edge to release the retaining clips. For extended cab (SuperCab), release the seat latch and fold the seat forward. Remove the seat back if necessary by removing lower mounting bolts at the base of the seat back.
2. 2

   Remove necessary interior trim panels
   Using panel removal tools, carefully pry off the lower B-pillar trim panels and rear door sill plates on the driver's side to expose wire routing paths. Remove the kick panel on the driver's side by releasing the retaining clips. Work slowly to avoid breaking plastic clips. Set trim pieces aside in a safe location.
3. 3

   Run power wire from battery to amplifier location
   Locate an existing grommet in the firewall on the driver's side (typically near the main wiring harness entry point). Make a small slit in the grommet if needed and route the power wire through using a fish wire or coat hanger. Install the in-line fuse holder within 18 inches of the battery positive terminal, but do not install the fuse yet. Route the wire along the existing wiring harness path under the rocker panel trim, securing with zip ties every 12-18 inches. Keep wire away from sharp edges and moving parts.
4. 4

   Establish ground connection for amplifier
   Locate a factory ground point near the amplifier mounting location (typically a bolt on the chassis or floor pan under the rear seat). Remove the existing bolt, clean both the chassis surface and ring terminal contact area with sandpaper or wire brush to bare metal. Attach the amplifier ground wire ring terminal to the bolt and reinstall. Ensure solid metal-to-metal contact for proper grounding.
   Torque spec

   Ground Bolt16 Nm (12 lb-ft)
5. 5

   Route RCA and remote turn-on wire
   Remove the factory head unit or radio trim panel to access the rear of the radio. Connect RCA cables to the subwoofer output (if equipped) or use a line-output converter on the rear speaker wires if no dedicated subwoofer output exists. Connect the remote turn-on wire to the blue/white wire at the radio harness (amplifier turn-on signal). Route RCA cables and remote wire through the same path as the power wire, but keep them separated by at least 6 inches to prevent noise interference. Use wire loom to protect cables.
6. 6

   Mount amplifier
   Position the amplifier in the chosen location ensuring adequate ventilation around cooling fins. Mark mounting hole locations. If mounting to carpet-covered surface, cut small holes in carpet to expose metal. Drill pilot holes if necessary and secure amplifier using appropriate fasteners. If using self-tapping screws into sheet metal, ensure they do not penetrate fuel tank, brake lines, or wiring harnesses on the opposite side.
7. 7

   Connect wiring to amplifier
   Connect the power wire to the amplifier's positive terminal, ensuring the connection is tight and secure. Connect the ground wire to the amplifier's ground terminal. Connect the RCA cables to the appropriate input jacks (typically labeled 'Sub In' or 'Input'). Connect the remote turn-on wire to the amplifier's remote terminal (usually labeled 'REM' or 'Remote'). Do not install the fuse in the power wire yet.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
8. 8

   Position and secure subwoofer enclosure
   Place the subwoofer enclosure in the desired location in the rear cabin area. For crew cab, this is typically behind the rear seat against the back wall. Secure the enclosure using mounting brackets or straps to prevent movement during driving. Ensure the enclosure does not interfere with seat operation or create a projectile hazard. In extended cab models, verify rear seat still folds properly with enclosure in place.
9. 9

   Run speaker wire from amplifier to subwoofer
   Measure and cut appropriate length of speaker wire to reach from amplifier to subwoofer. Maintain proper polarity by keeping track of positive and negative conductors. Strip wire ends and connect to amplifier's speaker output terminals and subwoofer terminals. Verify impedance matching between amplifier output and subwoofer load. Secure wire routing with zip ties to prevent rattling.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
10. 10

    Connect power wire to battery
    At the battery, strip the end of the power wire and attach a ring terminal. Connect the ring terminal to the positive battery post, ensuring a tight connection. Do not reconnect the negative battery terminal yet.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)
11. 11

    Initial system check and fuse installation
    Double-check all connections for proper polarity and secure attachment. Verify ground connection is solid. Set amplifier gain control to minimum and bass boost to off. Set low-pass filter to approximately 80 Hz as a starting point. Reconnect negative battery terminal. Insert fuse into the in-line fuse holder on the power wire. Turn ignition to accessory position and verify amplifier power LED illuminates. If LED does not illuminate, immediately disconnect battery and troubleshoot connections.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Reinstall all interior trim panels in reverse order of removal, ensuring all clips are properly seated
2. Reinstall rear seat, verifying all mounting points are secure and seat latches engage properly
3. Tuck all visible wiring out of sight and secure with zip ties to prevent rattling
4. Ensure no wires are pinched between trim panels or seat mounting points

Verification

• Turn vehicle to accessory mode and play audio source with bass content
• Verify subwoofer produces sound without distortion at moderate volume levels
• Check amplifier does not go into protect mode (indicated by protect LED or no sound output)
• Adjust amplifier gain using a multimeter or by ear to match subwoofer output with main speakers, starting at minimum and increasing gradually
• Test at various volume levels to ensure no clipping or distortion occurs
• Verify all interior trim panels are secure and no rattles are present from loose panels or wiring
• Check battery voltage with engine off (should be approximately 12.6V) and with engine running (should be 13.8-14.4V) to ensure electrical system is functioning properly with added load

More procedures for this vehicle