Welcome to the installation guide for your 2016–2023 Toyota Tacoma Alpine Plug & Play 4-Channel Amp & Powered 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
- Parts Included
- Tools Needed
- Step 1: Disassembling the Dash
- Step 2: Disassembling Your Tacoma
- Step 3: Routing the Power Wire
- Step 4: Routing the Main Harness
- Step 5: Making Connections to Your Head Unit
- Step 6: Installing the Bass Control Knob
- Step 7: Reinstall Your Head Unit
- Step 8: Connecting the Ground Wire
- Step 9: Modifying the Rear Storage Compartment
- Step 10: Installing the Rear Storage Compartment
- Step 11: Connecting the Power Wire to the Battery
- Step 12: Testing System Functionality
- Step 13: Reassembling Your Tacoma
- Common Troubleshooting Solutions
📢 Important Updates & Notes
Please check back here for any Important Updates or Notes!
🎥Installation Video
🛠️Parts Included:
- Amplifier assembly:
- Vehicle specific mounting bracket
- Alpine PWE-S8 powered subwoofer
- Alpine KTP-445U 4 channel amplifier
- T-Harness
- Main harness
- RCA adapters
- Power Cable
- 10 Zip Ties
- 10mm Ground Bolt
- Female and male bullet connector
🛠️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-by-Step Instructions
Step 1: Disassembling the Dash
- Pull the outer dash trim straight back toward you to remove it.
- Loosen the four 10mm bolts securing the radio bracket
Step 2: Disassembling Your Tacoma
- Remove the driver-side door sill by pulling straight up.
- Remove the driver-side kick panel:
- Twist the button retainer counterclockwise to remove it.
- Pull the kick panel out to detach it.
- Remove the driver-side rear door sill by pulling straight up.
- Remove the lower seat belt screw cover on the B-pillar.
- Use a 14mm socket to remove the bolt securing the lower seat belt mount.
- Pull back the weather seal on both sides of the B-pillar.
- Use a panel tool to release and remove the B-pillar cover.
- Remove the rear seat headrest on the driver side.
- Flip the driver-side rear seat down and remove the two screw covers on the lower part of the seat.
- Use a 14mm socket to remove the two mounting bolts from the lower part of the seat.
- Remove the seat back and set it aside.
- Use a 12mm socket to remove the two bolts on the bracket next to the C-pillar and remove the bracket.
- Remove the rear storage pocket:
- Use a 10mm socket to remove the two or three bolts securing the plastic compartment.
- Remove the plastic compartment.
- Pull back the weather seal from the C-pillar.
- Gently pull out on the C-pillar cover to remove it.
Step 3: Routing the Power Wire
- The kit includes a spyder-wrapped power wire with an inline fuse.
- Open the hood and secure it in place.
- Begin with the ring terminal near the positive battery terminal.
- Route the power wire along the driver’s side fender, toward the firewall, and through the driver-side firewall grommet.
- Use a utility knife to cut an "X" in the grommet.
- ⚠️Note: Many Toyota firewall grommets have both an exterior and interior membrane, so ensure you cut through both while avoiding damage to any vehicle wiring.
- To make routing easier, you may use a wire fish to pass the blue bullet connector end of the power wire into the vehicle’s cab.
- Once the power wire is inside, pull the slack into the driver’s floorboard.
- Continue routing the power wire through the factory wiring channel along the driver’s side, toward the rear seat.
- Secure any loose wiring in the engine bay using the provided zip ties.
Step 4: Routing the Main Harness
- Begin by connecting the amplifier and subwoofer near the area where the rear storage cubby was removed.
- Route the opposite end of the main harness (with the T-harness end) as follows:
- Start along the bottom of the C-pillar and follow the factory wiring channel near the driver-side rear door.
- Continue through the factory wiring channel under the B-pillar and along the wiring channel near the driver-side front door until you reach the front seat mount support.
- Route the T-harness end of the main harness under the carpet toward the transmission tunnel.
- Continue along the floor toward the front side of the center console (toward the dash).
- Guide the T-harness up into the lower dash cavity and toward the radio.
- At this stage, fully remove the radio to access the necessary connections.
- Run the T-harness inside the dash toward the main radio connections.
Step 5: Making Connections to Your Head Unit
Making connections to your 2016-2019 head unit:
Factory Head Unit:
- Disconnect the 10-pin and 6-pin connectors from the back of the head unit.
- Connect the male end of the Alpine T-Harness to the 10-pin and 6-pin locations on the back of the head unit.
- Connect the 10-pin and 6-pin connectors from the vehicle to the female end of the Alpine T-Harness.
Aftermarket Head Unit:
- Front Speakers:
- White to White
- Grey to Red
- Rear Speakers:
- Green to White
- Purple to Red
- Subwoofer:
- White to White
- Red to Red
- Disconnect the 10-pin and 6-pin connectors from the back of the head unit.
- Connect the male end of the Alpine T-Harness to the 10-pin and 6-pin locations on the back of the head unit.
- Connect the 10-pin and 6-pin connectors from the vehicle to the female end of the Alpine T-Harness.
- Connect RCA cables from the Alpine T-Harness to the RCA outputs on the aftermarket radio.
Making connections to your 2020-2023 head unit:
Factory Head Unit:
- Use the provided T-tap to connect to the Grey wire.
- Disconnect the 10-pin connector from the back of the head unit.
- Connect the male end of the Alpine T-Harness to the 10-pin location on the back of the head unit.
- Connect the 10-pin connector from the vehicle to the female end of the Alpine T-Harness.
- If needed, connect the provided blue remote wire (male bullet connector end) to the blue remote wire from the Alpine main harness
Aftermarket Head Unit:
- Front Speakers:
- White to White
- Grey to Red
- Rear Speakers:
- Green to White
- Purple to Red
- Subwoofer:
- White to White
- Red to Red
- Disconnect the 10-pin connector from the back of the head unit.
- Connect the male end of the Alpine T-Harness to the 10-pin location on the back of the head unit.
- Connect the 10-pin connector from the vehicle to the female end of the Alpine T-Harness.
- Use the provided bullet connectors to connect the remote turn-on wire (Blue with White Stripe) to the aftermarket head unit.
- Connect the RCA cables from the Alpine T-Harness to the RCA outputs on the aftermarket radio.
Step 6: Installing the Bass Control Knob
- Use a 9/32 drill bit to create an opening for the subwoofer level knob.
- It is highly recommended to use a panel blank for installation.
- Secure the knob in place using the provided nut, then attach the knob to the dial.
Step 7: Reinstalling Your Radio
- Ensure that all previously disconnected connections are securely reconnected.
- Place the head unit back into the dash and secure it using the four factory 10mm bolts.
- Do not fully reassemble the dash yet—functionality should be tested before completing the installation.
Step 8: Connecting the Ground Wire
- Use the provided Alpine ground wire.
- Attach the ring terminal to the factory rear seat bolt located under the rear middle seat bracket.
Step 9: Modifying the Rear Storage Compartment
- Trim the left side of the rear plastic compartment toward the center of the truck.
- A 2.5-inch hole saw can be used as an alternative method.
- Remove the trimmed plastic piece.
Step 10: Installing the Rear Storage Compartment
- Reinstall the C-pillar trim and press it into place.
- Place the rear storage compartment back into the truck.
- Route the main harness through the opening in the plastic.
- Connect the main Alpine harness to the amplifier.
- Secure the amplifier bracket to the plastic compartment using one of the provided bolts.
- ⚠️Note: Some vehicles may not have the lower bolt position.
- Position the subwoofer near the storage cubby and connect it to the subwoofer.
- Connect the White 14-pin connector to the subwoofer.
- Connect the RCA cables from the main harness to the subwoofer:
- Red to Red
- White to White
- Slide the subwoofer into the lower amplifier bracket.
- Secure the subwoofer bracket to the factory mounting locations using the provided bolts and standoff spacers.
Step 11: Connecting the Power Wire to the Battery
- Use a 10mm or 12mm wrench to remove the nut from the positive battery terminal.
- Place the ring terminal from the Alpine power wire onto the positive terminal and secure it with the factory nut.
- ⚠️ Note: A small spark may occur when connecting the ring terminal to the battery—this is completely normal.
Step 12: Testing System Functionality
- Power on your vehicle and verify that all components are functioning properly.
- Play a song that will run continuously for a few minutes.
- Check the Balance/Fade settings to ensure all speakers are playing correctly.
- Below is the recommended amplifier setting for use with an Aftermarket Head Unit:
Once you have confirmed that your system is working and the gains are adjusted to your preference, reassemble your vehicle and enjoy your newly amplified system!
Step 13: Reassembling Your Tacoma
- Reinstall the weather seal around the rear door.
- Reattach the seat bracket for the rear seat and secure it using the factory 12mm bolts.
- Reinstall the seat back and secure it with the factory 14mm bolts.
- Replace the bolt covers on the lower part of the back seat.
- Flip the seat up and reinstall the headrest.
- Press the B-pillar trim back into place.
- Secure the weather seal around the B-pillar.
- Tighten the 14mm bolt that secures the bottom seat belt mount.
- Reinstall the driver-side kick panel and secure it with the button retainer.
- Press the driver-side door sill and rear door sill back into place.
- Tighten the four 10mm bolts securing the radio.
- Press the dash trim back into place to complete reassembly.
Congratulations on installing your new Alpine 4 Channel Amplifier and Powered Subwoofer kit!
🛠️ Common Troubleshooting Solutions: Experiencing issues with your installation? Try these steps before reaching out for support.
1. Check the Connections Behind the Head Unit
If you have a factory head unit:
- Ensure the main vehicle connectors are fully seated.
- Verify the remote wire from the amplifier harness is properly connected to the radio using either a T-tap or T-harness.
- If using a T-tap, confirm that the connection is solid. A good connection will be indicated by the blue light on the subwoofer illuminating.
If you have an aftermarket head unit:
- Ensure the main vehicle connectors are fully seated.
- Verify that the RCA connections are fully plugged in.
- Check that the remote wire from the amplifier harness is connected to the radio harness.
- Make sure the subwoofer output is turned on in the head unit settings menu.
2. Check the Alpine Amplifier Settings
- Confirm that the front and rear gain settings are turned low/off.
- Double-check the dip switches on the amplifier—the recommended settings can be found in the installation guide.
3. Check the Subwoofer Settings
- Make sure the input selector is set to "Remote".
- Verify that the blue indicator light is on.
- Check that the gain and crossover dials are set to low/off.
- Ensure the RCA adapter is connected from the amplifier harness to the RCA inputs on the subwoofer.
If the RCA adapter is not connected, follow these steps:
- Locate the red 4 pin connector on the main harness near the subwoofer.
- Disconnect the male and female ends of the red 4 pin connector.
- Find the RCA adapter in the "Extra Parts" bag.
- Attach the male 4-Pin connector from the RCA adapter to the female red 4 pin connector.
- Connect the RCA's to the RCA inputs on the subwoofer.
- Play music and adjust the subwoofer gain to your preferred level.
4. Optimizing Sound Quality and Tuning Your System
Once you’ve confirmed all connections and ensured that the amplifier and subwoofer are functioning, follow these tuning recommendations for the best sound:
- If using a factory head unit, keep in mind that its output is voltage-regulated. This means that as you increase the volume, the head unit sends more power.
- If the amplifier gains are set too high with a low volume setting, your door speakers may peak before the subwoofer reaches its full potential.
Recommended Tuning Process:
- Turn the gain adjustments on both the amplifier and subwoofer all the way down (lowest setting).
- Play a song that will last for at least a few minutes.
- Increase the volume on the head unit to about 75% of max volume.
- Using a small flathead screwdriver, adjust the Front Gain setting on the amplifier until you reach your desired sound level.
- Repeat the process for the Rear Gain setting on the amplifier.
- Adjust the Sub Gain setting on the subwoofer.
- Fine-tune the Crossover setting on the subwoofer to your preferred level.
Final Adjustments & Sound Tweaks
- If you hear distortion, clipping, or the sound cuts out, the gain is set too high.
- Adjust the EQ settings within your head unit to fine-tune the sound.
- If using an aftermarket head unit, ensure that the subwoofer output is turned on in the head unit settings menu.
Contact Us
If you're still encountering difficulties and need additional troubleshooting support, please reach out using this contact form, and someone will get in touch as soon as possible.
