JBL Bypass with Kicker 5 Channel Amplifier Install Guide | 2014 - 2021 Tundra

Welcome to the installation guide for your JBL Amplifier Bypass Plug & Play Bundle with Kicker 5 Channel Amplifier for the 2014–2021 Toyota Tundra from Trail Grid Pro! This guide walks through removing the factory JBL amplifier beneath the front passenger seat, connecting the bypass harness, and wiring the Kicker 660.5 to your aftermarket radio. Read the full guide before starting.

Table of Contents

• Important Notes Before You Begin
• Installation Video
• Parts Included
• Tools Needed
• Step 1: Access the Area Under the Passenger Seat
• Step 2: Remove the Factory JBL Amplifier
• Step 3: Connect the JBL Bypass Harness
• Step 4: Remove the Door-Sill and Kick-Panel Trim
• Step 5: Connect the Radio’s RCA and Remote Leads
• Step 6: Route the RCA and Remote Leads
• Step 7: Route the Power Cable
• Step 8: Connect the Ground Wire
• Step 9: Connect the Amplifier Inputs and Speaker Outputs
• Step 10: Inspect the Wiring and Finish the Power Connection
• Step 11: Test the System
• Step 12: Set the Amplifier Controls
• Step 13: Reassemble and Complete the Final Checks
• Common Troubleshooting Solutions
• Contact Us

📢 Important Notes Before You Begin

Match your equipment: These instructions describe the factory-JBL Tundra installation with an aftermarket radio and Kicker 660.5. If your supplied connectors, amplifier, or vehicle layout differ, contact us before modifying anything.

Factory subwoofer: The subwoofer-output instructions below apply when amplifying the factory enclosure with this bypass harness. This Tundra harness uses red for subwoofer positive and black for subwoofer negative. Do not substitute wire pairings from a different vehicle or subwoofer setup.

Keep hardware organized: Photograph the factory wiring before unplugging it. Keep seat, amplifier, and trim fasteners separate so each returns to its original location.

🎥 Installation Video

Parts Included

• One Kicker 660.5 5-channel amplifier
• One plug-and-play JBL bypass harness
• Three pre-bundled 3-meter, 2-channel RCA cables with blue remote wire
• One RCA splitter with double female adapters
• Red power wire
• Kicker inline fuse block
• Black ground wire
• Four pieces of Velcro
• One male and one female bullet connector
• One supplied 10mm-head bolt

Check for shipping damage and missing parts before taking the vehicle apart. Contact us if anything is missing or damaged.

🛠️ Tools Needed

• 10mm socket and compatible ratchet
• 12mm wrench or socket for the battery-terminal hardware described in this kit
• 14mm wrench or socket for the passenger-seat bolts
• 3mm Allen wrench for amplifier and fuse-holder connections
• Panel removal tool, preferably plastic
• Phillips-head and small flat-head screwdrivers
• Utility knife
• Wire fish or suitable protected wire-pulling tool
• Electrical tape
• Side cutters
• Zip ties
• Appropriate crimping tool for the supplied bullet connectors
• Torque wrench for reinstalling the seat to Toyota’s specification

📝 Step-by-Step Instructions

Step 1: Access the Area Under the Passenger Seat

Complete the battery and seat-safety preparations above before starting.

1. Remove the two front 14mm-head passenger-seat mounting bolts.
2. Slide the seat forward to reach its rear mounting points.
3. Gently lift and pull back the two plastic covers over the rear bolts.
4. Remove the two rear 14mm-head bolts and keep all four seat bolts together.
5. Move the seat back and carefully tilt it to reach the amplifier underneath. Support the seat without pulling on its wiring.
6. If more room is needed, follow Toyota’s service procedure to disconnect the seat plugs, up to three in this installation, and lift the seat out with assistance.

Do not switch the vehicle on with seat connectors disconnected. If the seat cannot be supported safely with the wiring attached, stop rather than stretching the cables.

Step 2: Remove the Factory JBL Amplifier

1. Use a panel tool to remove the three black plastic retaining pins from the amplifier cover.
2. Lift off the black plastic cover.
3. Press the release tabs and unplug all three connectors from the side of the amplifier. Pull on the plug bodies, not the wires.
4. Lift the carpet flap to expose the amplifier mounting bracket.
5. Support the amplifier while removing its three 10mm-head mounting bolts.
6. Lift the factory amplifier out and save its hardware.

Step 3: Connect the JBL Bypass Harness

1. Locate the supplied bypass harness’s 10-pin and 12-pin connectors.
2. Match them to the corresponding factory plugs removed from the JBL amplifier.
3. Push each matching connection together until fully seated. Do not force a connector that does not align.

Step 4: Remove the Door-Sill and Kick-Panel Trim

The kick panel is the trim beside the front passenger’s feet. The door sill is the trim along the bottom of the doorway.

1. Unscrew the retaining knob holding the passenger-side kick panel.
2. Pull the panel toward the left, into the footwell, to release its retainers.
3. Set the panel and knob aside.
4. Use a panel tool or your fingers to gently lift the passenger-side door-sill trim until its clips release.
5. Lift the sill trim out of the vehicle.

Step 5: Connect the Radio’s RCA and Remote Leads

Access the back of the aftermarket radio using the vehicle- and radio-specific removal instructions. Support the radio instead of letting it hang by its wiring. RCA cables carry the audio signal; the blue remote wire tells the amplifier when to switch on.

1. Connect FL and FR to the radio’s front-left and front-right RCA outputs.
2. Connect RL and RR to its rear-left and rear-right outputs.
3. Connect SL and SR to its subwoofer outputs.
4. If the radio has only one subwoofer RCA output, connect the supplied Y-splitter to that output, then attach both subwoofer RCA leads using the supplied adapters as needed.
5. Use the supplied bullet connectors and a suitable crimping tool to connect the blue remote wire to the radio’s amplifier-turn-on lead.
6. Check that the remote connection is secure and insulated.

Step 6: Route the RCA and Remote Leads

1. Route the bundle down the passenger side of the dash toward the footwell.
2. Continue behind the upper edge of the carpet toward the bottom of the windshield-pillar area.
3. Open the factory wiring-channel covers by releasing their tabs with a small flat-head screwdriver.
4. Follow the channel toward the area under the passenger seat.
5. Pass the cables under the carpet and through the existing opening near the floor vents.
6. Keep cables clear of seat tracks, mounting holes, and the vents.

Step 7: Route the Power Cable

Keep the battery end disconnected and the inline fuse removed throughout this step.

1. Plan the fuse-block mounting position using the amplifier and wiring-kit requirements.
2. Connect the short shielded power-cable section to one side of the fuse block.
3. Connect the long shielded cable section to the other side.
4. Seat each protective grommet in its groove and tighten the connections with the appropriate Allen wrench.
5. Fit the Kicker fuse-block cover.
6. Route the long cable along the inside of the driver-side fender toward the firewall, then across to the passenger-side firewall grommet, as described for this installation.
7. Secure the cable away from hot components, sharp edges, and moving parts.
8. Inspect both sides of the passenger-side firewall grommet and identify a clear rubber area away from factory wiring.
9. If an opening is needed, carefully make a small X only in that clear rubber area. Some Toyota grommets have inner and outer membranes.
10. Use a protected wire-pulling tool to guide the cable through without damaging the grommet or existing wiring.
11. Route the cable behind the kick panel, along the factory wiring channel, and under the carpet to the amplifier location.
12. Connect it to the amplifier’s labeled positive power terminal and secure it with the appropriate Allen wrench, following the amplifier manual.

⚠️ Important: Never cut blindly into a firewall grommet.
If you cannot see and protect the wiring on both sides, stop and use a qualified installer. Keep the cable protected from metal edges and maintain the grommet’s protective seal. Do not connect the cable to the battery yet.

Step 8: Connect the Ground Wire

1. Connect the supplied black ground wire to the amplifier’s labeled ground terminal.
2. Secure it with the appropriate Allen wrench.
3. Route the wire under the carpet to the intended factory ground location under the seat.
4. Attach it using the supplied 10mm-head bolt.
5. Check that the connection is secure and the wire cannot catch in the seat tracks.

If you cannot identify the intended ground location, contact us rather than choosing an arbitrary seat or trim bolt.

Step 9: Connect the Amplifier Inputs and Speaker Outputs

1. Position the Kicker 660.5 under the passenger seat.
2. Check clearance for the seat, wiring, and floor vents. Allow the ventilation space required by the amplifier manual.
3. Plan to secure it using the supplied Velcro or suitable mounting brackets, but finish the wiring before permanent mounting.
4. Connect the RCA cables using their channel labels and the list below.
5. Connect the blue remote wire to the amplifier terminal labeled REM.

RCA input connections:

• Amp 1 L: FL, gray
• Amp 1 R: FR, blue
• Amp 2 L: RL, gray
• Amp 2 R: RR, blue
• Sub L: SL, gray
• Sub R: SR, blue

Match the printed channel and left/right labels rather than relying on color alone.

Speaker-output connections from the JBL bypass harness:

Match each wire to the amplifier’s printed output label. Place its fork terminal, the U-shaped metal connector, under the clamping plate and tighten the terminal screw securely. Check that no exposed strands or connectors touch adjacent terminals.

Rear speakers, Amp 2, bottom row in this installation:

• Left positive (+): green
• Left negative (−): green with black stripe
• Right positive (+): purple
• Right negative (−): purple with black stripe

Front speakers, Amp 1, top row in this installation:

• Left positive (+): white
• Left negative (−): white with black stripe
• Right positive (+): gray
• Right negative (−): gray with black stripe

Subwoofer outputs, only when amplifying the factory enclosure with this Tundra bypass harness:

• Sub negative (−), bottom row: black
• Sub positive (+), top row: red

Confirm the printed terminal labels and supplied harness before connecting. Contact us if your harness differs.

Step 10: Inspect the Wiring and Finish the Power Connection

1. Inspect every power, ground, remote, RCA, and speaker connection.
2. Check that wiring cannot be pinched by trim, the seat, or mounting bolts.
3. Confirm the fuse rating and fuse-holder placement against the amplifier and wiring-kit instructions.
4. With the battery still isolated and the inline fuse removed, attach the short power cable’s pre-fitted ring terminal to the positive (+) battery-terminal connection as directed by the vehicle and kit instructions.
5. Secure the amplifier and restore the passenger-seat wiring and mounting before powering the vehicle. Follow Toyota’s service procedure and specified seat-bolt torque.
6. Complete battery reconnection and fuse installation in the order required by the vehicle and amplifier instructions, only after all wiring is finished and checked.

Step 11: Test the System

1. Start with the radio volume low and amplifier gains at minimum.
2. Switch on the radio and check that the amplifier powers on.
3. Play a familiar track and check the front speakers, rear speakers, and subwoofer.
4. Use the radio’s balance and fader controls to help check each speaker location.
5. If sound is missing, distorted, or cutting out, stop and troubleshoot before increasing the volume.

Step 12: Set the Amplifier Controls

For the RCA-input arrangement in this guide, use these starting switch positions:

• Fader: ON
• Input Level: LO
• Sub Input: SUB

1. Follow the Kicker manual’s gain-setting procedure for your radio and amplifier. Gain matches the radio signal to the amplifier; it is not an extra volume control.
2. Choose a familiar track that will play for several minutes.
3. Use a clean, undistorted radio volume for adjustment. The original kit procedure uses about 75% of maximum volume, but not every radio stays clean at that level.
4. Starting at minimum, adjust Amp 1 gain for the front speakers with a small flat-head screwdriver, within the amplifier manual’s limits.
5. Repeat for Amp 2, then the subwoofer gain.
6. Reduce the gain and radio volume immediately if sound becomes distorted or cuts out. Investigate the cause before continuing.

⚠️ Important: Do not tune through distortion.
Clipping, distortion, or sound that stops can indicate a setup or wiring fault. Lower the volume and gains and inspect the installation. Ask a qualified audio installer if you are unsure how to set gains correctly. Make final radio EQ adjustments only after establishing clean sound.

Step 13: Reassemble and Complete the Final Checks

1. Turn the vehicle and audio system off before finishing trim work.
2. Confirm that the amplifier is secured and the wiring cannot catch in seat tracks or obstruct floor vents.
3. Close the wiring-channel covers without trapping any cables.
4. Refit the passenger-side kick panel and its retaining knob.
5. Press the door-sill trim back into place.
6. Reinstall the radio and dash trim using the vehicle-specific instructions.
7. Confirm that all four seat bolts were tightened to Toyota’s specification, then refit their covers.
8. Check the seat’s movement and verify that no wire catches or pulls tight.
9. Test the audio again and check for warning lights or other affected vehicle functions. If a seat or airbag warning appears, stop and have the system checked.

Keep the removed factory amplifier, cover, retaining pins, and mounting hardware together for future use. Do not refit a cover over the new amplifier unless it meets the amplifier’s clearance and ventilation requirements.

Congratulations on installing your JBL Amplifier Bypass Harness and Kicker 5 Channel Amplifier!

🛠️ Common Troubleshooting Solutions

The Radio Works, but There Is No Sound

Check whether the Kicker amplifier powers on. Before touching wiring, isolate power using the vehicle and amplifier procedures. Inspect the remote lead at the radio and REM terminal, the power and ground connections, and the bypass-harness plugs. Confirm the RCA leads reach the matching inputs.

The Factory Subwoofer Does Not Play

Check the radio’s subwoofer-output setting and Sub RCA connections. Confirm Sub Input is set to SUB for this arrangement. With power isolated, check the Tundra bypass harness’s red positive and black negative leads at the labeled subwoofer outputs. Do not use wire pairings from another vehicle’s harness.

Front and Rear Sound Do Not Match the Radio Controls

With power isolated, compare the FL, FR, RL, and RR cable labels at both ends. Confirm that Amp 1 serves the front speakers and Amp 2 serves the rear speakers. Do not rely on RCA connector color alone.

Sound Is Distorted or Cuts Out

Lower the volume and gains. With power isolated, check for loose connections, stray wire strands, damaged cables, and an insecure ground. Check ventilation and follow the amplifier manual for protection indicators. Do not replace a fuse with a higher rating to hide a fault.

A Connector or Ground Location Does Not Match

Stop before modifying anything. Send us your Tundra’s model year, radio and amplifier models, and clear photos of the supplied harness and the connection in question.

Contact Us

Need help? Use our contact form and include your Tundra’s model year, radio and amplifier models, a description of the issue, and clear photos of the relevant wiring.