2014-2021 Tundra Alpine Plug & Play 5-Channel Amplifier Kit Installation Guide

2014-2021 Tundra Alpine Plug & Play 5-Channel Amplifier Kit Installation Guide

Welcome to the installation guide for your 2014-2021 Tundra Alpine Plug & Play 5-Channel Amp & Subwoofer Kit from Trail Grid Pro! This step-by-step guide is designed to make the installation process as smooth as possible, whether you're a seasoned DIYer or tackling your first head unit upgrade.

In this guide, you’ll find:

  • 📢 Important Updates: The written guide includes the latest updates and adjustments that may not be shown in the video, ensuring you have the most up-to-date instructions for a flawless installation.
  • 🎥 Installation Videos: Visual instructions to help you through the process, including a detailed microphone install.
  • 🛠️ Parts Included and Tools Needed: A quick list of everything you'll need to get started.
  • 📝Step-by-Step Instructions: Clear, easy-to-follow directions from disassembling your dash to securing the new Sony head unit.
  • ⚠️ Special Notes: Important information and considerations for your installation.
  • 🛠️ Common Troubleshooting Solutions: Quick and effective fixes for common installation and performance issues.

Table of Contents

🎥Installation Video

Coming Soon!

🛠️Parts Included:

  • Alpine S2-A55V 5-Channel Amplifier
  • AudX Tundra Amplifier Mounting Bracket
  • AudX T-Harness
  • AudX Main harness
  • Amplifier Bypass Harness (Amplified Non-JBL Vehicles Only)
  • RCA adapters
  • Trail Grid Pro Amplifier Install Kit
  • 10 Zip Ties
  • 10mm Ground Bolt

🛠️Tools Needed:

  • Panel removal tool
  • 10 mm socket
  • 12 mm socket
  • 14 mm socket
  • Ratchet wrench
  • Socket extension
  • Phillips head screwdriver
  • Zip ties
  • Razor knife
  • Wire fish

Step 1: Disassembling the Dash

  • Remove the lower dash panel that contains the USB ports.
    • Insert a panel removal tool into the gap between this panel and the HVAC panel. Once loosened, pull straight back to release the retaining clips.
  • Pull the HVAC panel straight out using your hands.
  • Disconnect the single plug from the back of the HVAC control panel.
  • To remove the factory head unit:
    • Use a 10 mm socket and extension to remove the four 10 mm bolts securing the bottom of the radio. Store them in the cup holder for safekeeping.
    • Pull the head unit straight back to release the upper retaining clips.
    • Disconnect all wiring connections from the back of the radio by pressing the tabs on each connector and unplugging them.

Step 2: Disassembling Your Tundra

Remove the center console:

  • Twist the gear shifter handle counterclockwise to remove it.
  • Open the center console.
  • Lift up on the shifter panel to remove it.
    • Disconnect any wire connections before fully removing.
    • Pull straight out to release the retaining tabs.
    • Disconnect any connectors before removing the panel completely.

Removing the front passenger seat:

  • Remove two 14 mm bolts holding the passenger front seat bracket in place.
  • Slide seat forward to access the rear seat bolts.
  • Gently lift up while pulling back on trim to remove the two plastic trim pieces covering the rear 14 mm bolts.
  • Remove the two 14 mm bolts.
  • Slide seat back, lift up and lean back to give access under seat or unplug up to three plugs and remove seat from vehicle.

Remove the factory Non-JBL amplifier (Amplified Non-JBL Vehicles Only):

  • Remove the three black plastic hold down pins using a panel tool.
  • Remove black plastic cover over amplifier.
  • Remove all three plugs located on the side of the amplifier.
  • Lift the carpet flap to expose the amplifier mounting bracket.
  • Remove the three 10 mm bolts holding amplifier to vehicle and remove from the vehicle.

Step 3: Connecting the amplifier bypass harness (Amplified Non-JBL Vehicles Only)

  • The bypass harness has two plugs:
    • One 10 pin connector.
    • One 12 pin connector.
  • Match the appropriate connectors to the factory plugs and connect.

Step 4: Removing door sill and kick panel trim:

  • Passenger front door kick panel trim:
    • Remove screw on knob securing panel to floor.
    • Pull the panel to the left to remove the retainers.
    • Passenger door sill:
      • Using a panel tool or your fingers gently pry the floor trim up until free.
      • Lift and remove from vehicle.

Step 5: Routing the Power Wire

  • Prepare the Power Wire:
    • Open the hood and secure it in place.
    • Locate the power wire with the inline fuse included in your kit.
    • Connect the short power wire to one side of the inline fuse by securing the wire ferrule using a 3 mm Allen key.
    • Connect one end of the longer power wire to the other side of the inline fuse the same way.
  • Route the Power Wire:
    • Place the ring terminal near the positive battery terminal (do not connect it yet).
    • Route the power wire along the driver’s side fender, across the firewall, and toward the passenger-side firewall grommet.
  • Pass Through the Firewall:
    • Use a utility knife to carefully cut an "X" in the firewall grommet to allow the power wire to pass through.

      ⚠️ Note: Many Toyota firewall grommets have both an exterior and interior membrane—cut through both.
      ⚠️ Be careful not to damage any vehicle wiring while cutting.

    • Use a wire fish tool if necessary to guide the ferrule end of the power wire into the cab.
    • Once the wire is through the firewall, pull the slack into the passenger-side floorboard.
  • Run the Power Wire to the Amplifier:
    • Route the wire down the passenger-side kick panel and through the factory wire channel.
    • Run the wire under the carpet to the power side of the amplifier.
    • Use the provided zip ties to secure any loose wiring in the engine bay.

Step 4: Routing the Main Harness

  • Route the Main Harness:
    • Position the main harness under the front passenger seat.
    • Start with the T-harness end and begin routing it toward the head unit.
    • Run the harness under the carpet, directing it toward the gear shifter.
    • Continue routing the harness through the transmission tunnel area, moving toward the front of the vehicle.
    • Guide the T-harness up inside the dash, routing it towards the main radio connections.

Step 5: Making Connections to Your Head Unit

For 2014–2019 Models

Factory Head Unit:

  • Disconnect the 10-pin and 6-pin and from the back of the head unit.
  • Plug the male end of the AudX T-Harness into the 10-pin and 6-pin ports on the head unit.
  • Attach the vehicle’s 10-pin and 6-pin connectors to the female end of the AudX T-Harness.
  • ⚠️ (Optional) If grounding the harness, secure the black wire with the small ring terminal to a clean metal-to-metal ground location.

Aftermarket Head Unit:

  • Disconnect the 10-pin and 6-pin connectors from the back of the head unit.
  • Connect the male end of the AudX T-Harness to the 10-pin and 6-pin ports on the head unit.
  • Attach the vehicle’s 10-pin and 6-pin connectors to the female end of the AudX T-Harness.
  • Connect RCA cables to the RCA outputs on the aftermarket radio.

For 2020–2021 Models

Factory Head Unit:

  • Disconnect the 10-pin and AM/FM antenna connector from the back of the head unit.
  • Connect the male end of the AudX T-Harness to the 10-pin and AM/FM antenna port on the head unit.
  • Attach the vehicle’s 10-pin and AM/FM antenna connector to the female end of the AudX T-Harness.
  • If you choose to ground the harness, secure the black wire with small ring terminal to ground location, ensuring it is a good metal to metal contact. 

Aftermarket Head Unit:

  • Disconnect the 10-pin and AM/FM antenna connector from the back of the head unit.
  • Connect the male end of the AudX T-Harness to the 10-pin and AM/FM antenna location on the head unit.
  • Attach the vehicle’s 10-pin and AM/FM antenna connector to the female end of the AudX T-Harness.
  • Connect RCA cables to the RCA outputs on the aftermarket radio:
    • Front Speakers:
      White → White
      Grey → Red
    • Rear Speakers:
      Green → White
      Purple → Red
    • Subwoofer:
      Orange → White
      Brown → Red
  • ⚠️ (Optional) If grounding the harness, secure the black wire with the small ring terminal to a clean metal-to-metal ground location.

Step 6: Reinstall Your Head Unit

  • Reconnect and Reposition:
    • Ensure that all previously disconnected wiring connections are securely reattached.
    • Carefully position the head unit back into the dash.
    • Fasten the head unit using the four factory 10 mm bolts.

⚠️ Important: Do not fully reassemble the dash at this point—functionality should be tested before completing the installation.

Step 7: Connecting the Ground Wire

  • Secure the Ground Connection:
    • Use the provided ground wire to connect the ring terminal to the factory ground point located under the passenger seat.
    • If a factory ground bolt is not present, use the included bolt to secure the ring terminal to the pre-threaded hole under the seat.

Step 8: Connecting the Bass Control Knob

  • Mount and Connect the Bass Knob:
    • Attach the bass control knob in your preferred location using the included Velcro, or install it into one of our Switch Blank Mounts.
    • Route the control knob wire from the main harness and plug the 3.5mm headphone jack into the bass control knob.
    • Use zip ties to secure any excess or loose wiring.

Step 9: Mount Amplifier to Amplifier Mounting Bracket

  • Install the Amplifier:
    • Place the amplifier mounting bracket with the AudX label facing up.
    • Align the amplifier with the pre-drilled holes on the mounting bracket, orienting it so the RCA ports face the rear of the vehicle.
    • Insert one bolt up through the bottom of the amplifier mounting bracket, then through the amplifier’s mounting hole.
    • Place a flat washer, followed by a split washer, and secure it with a nut.
    • Use a 9/32" wrench and a Phillips head screwdriver to tighten the hardware.
      ⚠️ Do not overtighten.
    • Mount the amplifier bracket to the floor pan using the factory hardware by securing the 10 mm bolts back to the factory locations.

Step 10: Making Connections To Amplifier

  • RCA Input Harness:
    • Use a Phillips-head screwdriver to remove one screw from the amplifier's control faceplate.
    • Place the ring terminal from the ground wire over the screw.
    • Re-secure the screw to fasten the ground.
  • Connect the RCA's:
    • CH-1 L - FL White
    • CH-2 R - FL Grey
    • CH-3 L - RL Green
    • CH-4 R - RR Purple
    • Sub L - SL Orange
    • Sub R - SR Brown
  • Connect the Remote Wire:
    • Insert the remote wire ferrule into the REM input on the amplifier.
    • Tighten the screw using a 2 mm Allen wrench.
    • Connect the harness to the 4-pin connector on the main harness.
  • Wire Ferrule Harness
    • Connect the harness to the 8-Pin connector on main harness. 
  • Make the following speaker connections:
    • Rear speaker leads on the bottom row: 
      • CH-1 - White/Black Stripe
      • CH-2 - Grey/Black Stripe
      • CH-3 - Green/Black Stripe
    • CH-4 - Purple/Black Stripe
  • Front speaker leads on the top row:
      • CH-1 + White
      • CH-2 + Grey
      • CH-3 + Green
      • CH-4 + Purple
  • Subwoofer Wire
    • Connect wire ferrule ends to amplifier:
      • Sub - Black Wire
      • Sub + Red Wire
  • Connect Ground and Power Wires:
    • Connect the provided black ground wire to the amplifier and secure it using a 2 mm Allen wrench.
    • Connect the power wire to the amplifier and secure it with a 2 mm Allen wrench.

Step 11: Route Subwoofer Wire

  • Route the wire to behind the rear seat:
    • Remove the rear door sill by pulling straight up.
    • Route the subwoofer wire through the factory wiring channel toward the rear seat.
    • Press the subwoofer wire under the interior plastic panels and continue routing it to the rear seat.
  • Connect to the Subwoofer:
    • Connect the yellow wire to the positive (+) terminal.
    • Connect the black wire to the negative (–) terminal.

    Step 12: Connect Power To Battery

    • Connect the Power Wire:
      • Locate the short length of power wire with the pre-connected ring terminal.
      • Connect the ring terminal securely to the positive battery terminal.

    Step 13: Test System

    • Power On and verify functionality:
      • Turn on your vehicle and test the audio system.
      • Confirm that both the radio and amplifier are functioning properly.

    🛠️Troubleshooting Tip:
    If the head unit powers on but you hear no sound, double-check that the remote turn-on wire is properly connected.

    Step 14: Tune The Amplifier

    • Set Initial Amplifier Settings:
      • On your Alpine S2-A55V amplifier, set the following:
        • Fader: ON
        • Input Level: LO
        • Sub Input: SUB
    • Adjust Gain Levels:
      • Choose a song that plays continuously for a few minutes.
      • Turn the volume on your head unit to about 75% of the maximum volume.
      • Using a small flathead screwdriver, adjust the Amp 1 gain (Front Speakers) to your desired sound level.
      • Repeat the process for the Amp 2 gain (Rear Speakers).
      • Adjust the Sub gain last to set your desired bass level.
        • ⚠️ Warning: If you hear distortion, clipping, or audio cutting out, the gain is set too high—reduce accordingly.
    • Final Adjustments:
      • Use your head unit’s built-in EQ settings to fine-tune the overall sound to your personal preference.

    Step 15: Reassembly

    • Reinstall the Seat:
      • Once you’ve confirmed the system is functioning properly and your amplifier gains are set, begin reassembly.
      • Place the passenger seat back into position, aligning the rear seat mounts.
      • Start all four 14 mm seat bolts by hand, then tighten them using a 14 mm socket.
    • Finish Reassembling the Vehicle:
      • Reinstall all remaining components, including the rest of the seat, center console, and dash panels.

    Congratulations on installing your new Alpine 5 Channel Amplifier Plug & Play Kit! 

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