Welcome to the installation guide for your 2010-2024 4Runner 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
- Important Updates
- Installation Video
- Tools Needed
- Step 1: Disassembling the Dash
- Step 2: Disassembling your 4Runner
- Step 3: Routing the Power Wire
- Step 4: Routing the Main Harness
- Step 5: Making Connections to Your Head Unit
- Step 6: Reinstall Your Head Unit
- Step 7: Connecting the Ground Wire
- Step 8: Connecting the Bass Control Knob
- Step 9: Mounting the Amplifier to the Mounting Bracket
- Step 10: Making Connections to the Amplifier
- Step 11: Routing the Subwoofer Wire
- Step 12: Connect Power to the Battery
- Step 13: Test the System
- Step 14: Tune the Amplifier
- Step 15: Reassembly
🎥Installation Video
🛠️Parts Included:
- Alpine S2-A55V 5-Channel Amplifier
- AudX 4Runner Amplifier Mounting Bracket
- AudX T-Harness
- AudX Main harness
- RCA adapters
- Trail Grid Pro Amplifier Install Kit
- 10 Zip Ties
- 10mm Ground Bolt
🛠️Tools Needed:
- Panel removal tool
- 10mm socket
- 12mm socket
- 14mm socket
- Ratchet wrench
- Socket extension
- Phillips head screwdriver
- Zip ties
- Razor knife
- Wire fish
Step 1: Disassembling the Dash
- Remove the Side Panels:
- Pull straight out on both left and right side panels to remove them.
- Remove the HVAC Control Panel:
- Gently pull out the HVAC control panel.
- Disconnect the HVAC wiring harness by unplugging the connector in the back.
- Use a small flathead screwdriver or panel tool to release the retaining clip securing the connection.
- Remove the Head Unit Mounting Bolts:
- Locate the four 10mm bolts underneath the head unit.
- Remove them using a 10mm socket wrench or an impact gun.
- ⚠️Pro Tip: Place the bolts in the cup holder to avoid losing them.
- Remove the Factory Head Unit:
- Gently pull out one side of the head unit to loosen it.
- Move to the other side and repeat the process.
- Once loosened, grab the center and pull straight out to remove the head unit.
- Place a microfiber towel over the shift knob to prevent scratches or damage.
- Gently pull out one side of the head unit to loosen it.
- Disconnect All Wiring Connections:
- Unplug all wiring harnesses from the back of the head unit one at a time.
- Some connectors may be difficult to remove—use a small flathead screwdriver to press the release tab and pull out.
- Remove the Bracket & Final Connection:
- Identify the bracket on the back of the head unit, which is secured by a connector and tape.
- Either disconnect the connector or cut the tape to fully detach the bracket.
Step 2: Disassembling Your 4Runner
- Remove the Center Console:
- If equipped with a manual 4WD gear shifter, twist the handle counterclockwise to remove it.
- Twist the gear shifter handle counterclockwise to remove it.
- Lift up on the shifter panel to detach it.
- Disconnect any wire connections before fully removing the panel.
- Use a pry tool to lift and remove the lower trim panel.
- Remove the Trim Panel with 12V Outlet and USB:
- Remove the two 10mm bolts securing the trim panel.
- Pull the panel straight out to release the retaining tabs.
- Disconnect any connectors before removing the panel completely.
-
- Pull the panel straight out to release the retaining tabs.
- Disconnect any connectors before removing the panel completely.
- Remove the Passenger Front Seat:
- Lift the passenger front door sill plate straight up to remove it.
- Remove the plastic nut securing the passenger-side kick panel.
- Pull the kick panel straight out to detach it.
- Remove the plastic covers from the front seat bolt brackets.
- Use a 14mm socket to remove the front seat bolts.
- Move the seat into the forward position.
- Remove the plastic covers from the rear seat brackets.
- Use a 14mm socket to remove the rear seat bolts.
- Move the seat to the middle position and lean it back to access the underside.
- Disconnect all wiring connectors by pressing the release tabs.
- Carefully remove the seat from the vehicle.
Step 3: 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 3mm 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.
- Use a utility knife to carefully cut an "X" in the firewall grommet to allow the power wire to pass through.
- 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.
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- Remove the radio to access the connection points.
- Guide the T-harness up inside the dash, routing it towards the main radio connections.
Step 5: Making Connections to Your Head Unit
For 2010–2019 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 2020–2024 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
- Front Speakers:
- ⚠️ (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 10mm 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 passenger door.
- 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.
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.
- Use a Phillips-head screwdriver to remove one screw from the amplifier's control faceplate.
- 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 2mm 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
- Rear speaker leads on the bottom row:
- 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 wire ferrule ends to amplifier:
- Connect Ground and Power Wires:
- Connect the provided black ground wire to the amplifier and secure it using a 2mm Allen wrench.
- Connect the power wire to the amplifier and secure it with a 2mm Allen wrench.
Step 11: Route Subwoofer Wire
- Route the Wire to the Rear Cargo Area:
- Remove the rear door sill by pulling straight up.
- Route the subwoofer wire through the factory wiring channel toward the rear cargo area.
- Press the subwoofer wire under the interior plastic panels and continue routing it to the cargo area.
- 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
- On your Alpine S2-A55V amplifier, set the following:
- 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 and Mounting Bracket:
- Once you’ve confirmed the system is functioning properly and your amplifier gains are set, begin reassembly.
- Line up the mounting holes on the amplifier mounting bracket with the rear seat bolt holes.
- Place the passenger seat back into position, aligning the rear seat mounts with the amplifier bracket.
- Start all four 14mm seat bolts by hand, then tighten them using a 14mm socket.
- When installed correctly, the amplifier bracket should be sandwiched between the seat mounts and the floor, with the bolts running through the bracket tabs.
- Finish Reassembling the Vehicle:
- Reinstall all remaining components, including the rest of the seat, center console, and dash panels.