Installation Guide
Plug-and-Play Harness & Amplifier Rack Installation Guide
For Yamaha Boats | All Product Lines | DIY Edition
⚠ Safety warnings
- Turn the boat completely OFF before beginning any installation.
- Switch OFF all battery switches before touching any wiring.
- Never work on electrical connections with power present — risk of short circuit, fire, or equipment damage.
- Install battery fuse only as the FINAL step after all wiring is landed and secured.
- Verify no wire strands are crossing or capable of shorting before restoring power.
This guide covers the installation of all four Boat Harnesses product lines for Yamaha boats. Locate your product in the table below, then jump directly to that section. Review the Recommended Tools and Materials at the start of your section before purchasing supplies or beginning work.
| Product | Compatible Amps | Install Type | Section |
|---|---|---|---|
| PNP Harness Kit | Wetsounds / Hertz | Standalone harness — addition to or replacement of factory amp(s) | Section 1 |
| PNP Harness Kit | Aquatic AV | Standalone harness — addition to or replacement of factory amp | Section 2 |
| PNP Amplifier Rack Package | Wetsounds / Hertz | Replaces factory amp(s) in OEM location | Section 3 |
| PNP Amplifier Rack Package | Aquatic AV | Replaces factory amp in OEM location | Section 4 |
Section 1 — PNP Harness Kits: Wetsounds / Hertz
Standalone harness — addition to or full replacement of factory amp(s)
Where's your factory amp?
- On Wet Sounds / Hertz-equipped Yamaha boats, the factory amp is on the back of the bow seat.
Recommended Installation Tools
| Tool | Notes |
|---|---|
| Adhesive-Lined Heat Shrink | Assorted sizes. Use adhesive-lined (dual-wall) tubing for a waterproof seal on all exposed connections. |
| Tape Assortment | Exterior-grade Tesa tape for wire bundling and harness protection; electrical tape for general insulation. |
| Zip Ties | Assorted sizes for securing wire runs and harnesses away from moving parts and heat sources. |
| Wire Strippers | For preparing speaker wire and any additional signal or power leads. |
| Fish Tape / Pull Rod | Required when routing wire through towers or to subwoofer locations. A flexible fiberglass rod works best in tight boat cavities. |
| Insulated Heat Shrink Butt Connectors & Spades | Use with a proper ratcheting crimper — never use non-ratcheting pliers. Match connector gauge to wire gauge. |
| Ratcheting Crimper | Ensures a consistent, full crimp every time. Required for reliable connections. |
| Heat Gun or Torch | For activating adhesive-lined heat shrink and properly sealing butt connectors. |
| #10 Screws | For securing amplifier racks to the seat-back bump-outs. Minimum of 4 screws recommended. |
| #8 Screws | For securing standalone (individual) amplifiers in their mounting location. |
| Standard Drill and Bits | For pilot holes before driving mounting screws. Prevents substrate cracking. |
| Torx and Allen Bits | Required for fuse holder terminals and power distribution block terminal screws — check your specific hardware before starting. |
Recommended Installation Materials
Always use tinned OFC (Oxygen-Free Copper) speaker wire. Do not use CCA (Copper-Clad Aluminum) — CCA wire has higher resistance and degrades faster in marine environments and can lead to premature failure.
| Application | Recommended Gauge | Wire Type |
|---|---|---|
| Additional speakers, 4-ohm subwoofers | 16 AWG | Tinned OFC |
| 2-ohm or lower subwoofers | 12 AWG | Tinned OFC |
Note
- Power and ground runs to any new amplifier must use proper marine-grade power wire sized for the amplifier's rated current draw. Run from the house battery with a fuse holder mounted as close to the battery as possible. Leave the fuse out until installation is fully complete.
What's in the Box
Kit contents vary by brand and boat configuration. Identify your kit below before proceeding.
| Configuration | Harness Count |
|---|---|
| Wetsounds — 1 amplifier, no subwoofer | 1 kit / 2 harnesses |
| Wetsounds — 1 amplifier, with subwoofer | 1 kit / 3 harnesses |
| Wetsounds — 2 amplifier setup | 2 kits total: one 3-harness kit + one 2-harness kit |
| Hertz — 1 amplifier | 1 kit / 2 harnesses |
| Hertz — 2 amplifier setup | 2 kits / 4 harnesses total |
Installation — Addition of a New Amplifier (Factory Amp Retained)
Use this workflow when keeping the factory amplifier in place and adding a new amplifier for additional speakers. The harness installs between the factory amplifier and factory harness, acting as a tee to pass signal through while providing RCA outputs for the new amplifier.
- Power down completely. Turn the boat off and switch all battery switches off.
- Locate the factory amplifier (see "Where's your factory amp?" above).
- Unplug the factory harness from the factory amplifier.
- Install the Boat Harnesses adapter between the factory harness and the factory amplifier: plug the factory harness into the adapter, then plug the adapter back into the factory amplifier. The amplifier remains in place.
- Connect the RCA pigtails from the adapter to your new amplifier. RCA outputs are pre-configured for the zone discussed at time of purchase.
- Run a remote turn-on wire from the harness remote output to the remote input of your new amplifier.
- For additional speakers (tower speakers, subwoofers): run speaker wire from the install location to the new amplifier. Crimp appropriate spades onto the wire ends and adapt into the provided speaker wire whips.
- Run dedicated power and ground from the house battery to the new amplifier location. Mount a fuse holder as close to the battery as possible. Leave the fuse out.
- Land power and ground to the new amplifier. Verify no wire strands are crossing or capable of contacting adjacent terminals.
- Final check. Confirm all connections are secure and wiring is routed away from moving parts and heat sources. Install the battery fuse and restore power to test.
Installation — Full Replacement of Factory Amplifier(s)
Use this workflow when replacing all factory amplifiers with aftermarket units. Harnesses will have a single termination end with pre-configured RCA outputs matched to your specific boat and setup discussed at time of purchase.
Channel Map
| Channels | Speaker Zone |
|---|---|
| 1 – 2 (cabin/bow amp harness) | Bow and cabin speakers |
| 3 – 4 (cabin/bow amp harness) | Rear swim platform speakers |
| 5 – 6 (cabin/bow amp harness) | Subwoofer (if applicable) |
| 1 – 2 (tower amp harness) | Tower speakers |
- Power down completely. Turn the boat off and switch all battery switches off.
- Locate and remove all factory amplifiers (see "Where's your factory amp?" above). Unplug all harnesses from each factory amplifier and remove the amplifiers.
- Identify your harnesses. Lay out all supplied harnesses. Each connector is keyed to a specific factory harness and will only seat correctly on its intended plug.
- Adapt all harnesses. Plug each supplied adapter into the corresponding factory harness that was unplugged from the stock amplifier. Verify each connection is fully seated and locked.
- Connect to your new amplifier(s) per the channel map above.
- Run RCA signal cables from the RCA pigtails to the RCA inputs of your new amplifier. Keep RCA runs separated from power wire.
- Run a remote turn-on wire from the harness remote output to the remote input of your new amplifier.
- For additional speakers (tower speakers, subwoofers): run speaker wire from the install location to the amplifier. Crimp appropriate spades onto the wire ends and adapt into the provided speaker wire whips.
- Run dedicated power and ground from the house battery to your new amplifier(s). Mount a fuse holder as close to the battery as possible. Leave the fuse out.
- Land power and ground to the amplifier(s). Verify no wire strands are crossing or capable of contacting adjacent terminals. Torque all terminal screws securely.
- Final check. Confirm all connections are secure and wiring is routed away from moving parts and heat sources. Install the battery fuse and restore power to test.
Section 2 — PNP Harness Kits: Aquatic AV
Standalone harness — addition to or full replacement of factory amp
Recommended Installation Tools
| Tool | Notes |
|---|---|
| Adhesive-Lined Heat Shrink | Assorted sizes. Use adhesive-lined (dual-wall) tubing for a waterproof seal on all exposed connections. |
| Tape Assortment | Exterior-grade Tesa tape for wire bundling and harness protection; electrical tape for general insulation. |
| Zip Ties | Assorted sizes for securing wire runs and harnesses away from moving parts and heat sources. |
| Wire Strippers | For preparing speaker wire and any additional signal or power leads. |
| Fish Tape / Pull Rod | Required when routing wire through towers or to subwoofer locations. A flexible fiberglass rod works best in tight boat cavities. |
| Insulated Heat Shrink Butt Connectors & Spades | Use with a proper ratcheting crimper — never use non-ratcheting pliers. Match connector gauge to wire gauge. |
| Ratcheting Crimper | Ensures a consistent, full crimp every time. Required for reliable connections. |
| Heat Gun or Torch | For activating adhesive-lined heat shrink and properly sealing butt connectors. |
| #10 Screws | For securing amplifier racks to the seat-back bump-outs. Minimum of 4 screws recommended. |
| #8 Screws | For securing standalone (individual) amplifiers in their mounting location. |
| Standard Drill and Bits | For pilot holes before driving mounting screws. Prevents substrate cracking. |
| Torx and Allen Bits | Required for fuse holder terminals and power distribution block terminal screws — check your specific hardware before starting. |
Recommended Installation Materials
Always use tinned OFC (Oxygen-Free Copper) speaker wire. Do not use CCA (Copper-Clad Aluminum) — CCA wire has higher resistance and degrades faster in marine environments and can lead to premature failure.
| Application | Recommended Gauge | Wire Type |
|---|---|---|
| Additional speakers, 4-ohm subwoofers | 16 AWG | Tinned OFC |
| 2-ohm or lower subwoofers | 12 AWG | Tinned OFC |
Note
- Power and ground runs to any new amplifier must use proper marine-grade power wire sized for the amplifier's rated current draw. Run from the house battery with a fuse holder mounted as close to the battery as possible. Leave the fuse out until installation is fully complete.
What's in the Box
Your kit includes two harnesses. Aquatic AV-equipped Yamaha boats run a single factory amplifier located under the helm near the steering wheel. The two harnesses are different connectors — they are keyed so there is no possibility of incorrect installation.
AR250 note
- AR250: the factory Aquatic AV amp is in the driver's helm cubby beneath the steering wheel. The cubby usually fits one 5 or 6 channel amp (a second amp can sometimes mount on the bottom left face of the cubby). Amp racks mount on the back of the bow seat instead, so AR250 rack installs need the extension option on our Yamaha Aquatic AV (AAV) Amp Harness: at least 5 ft ($10 per foot) to reach.
Channel Map
| Channels | Speaker Zone |
|---|---|
| 1–2 | Bow and cabin speakers |
| 3–4 | Rear swim platform speakers |
Installation — Addition of a New Amplifier (Factory Amp Retained)
Use this workflow when keeping the factory amplifier in place and adding a new amplifier for additional speakers.
- Power down completely. Turn the boat off and switch all battery switches off.
- Locate the factory Aquatic AV amplifier under the helm near the steering wheel.
- Unplug the factory harnesses from the factory amplifier.
- Install the Boat Harnesses adapters between the factory harnesses and the factory amplifier: plug each factory harness into its corresponding adapter, then plug the adapters back into the factory amplifier. The connectors are different and will only fit in the correct positions.
- Connect the RCA pigtails from the adapter harnesses to your new amplifier. Outputs are pre-configured for the zone discussed at time of purchase.
- Run a remote turn-on wire from the harness remote output to your new amplifier.
- For additional speakers: run speaker wire from the install location to the new amplifier. Crimp appropriate spades onto the wire ends and adapt into the provided speaker wire whips.
- Run dedicated power and ground from the house battery to the new amplifier location. Mount a fuse holder as close to the battery as possible. Leave the fuse out.
- Land power and ground to the new amplifier. Verify no wire strands are crossing or capable of contacting adjacent terminals.
- Final check. Confirm all connections are secure. Install the battery fuse and restore power to test.
Installation — Full Replacement of Factory Amplifier
- Power down completely. Turn the boat off and switch all battery switches off.
- Locate the factory Aquatic AV amplifier under the helm near the steering wheel. Unplug both factory harnesses and uninstall the amplifier.
- Adapt the two supplied harnesses into the two stock boat harnesses that were unplugged. The connectors are different — each will only fit its correct counterpart.
- Connect to your new amplifier per the channel map above: channels 1–2 = bow and cabin; channels 3–4 = swim platform.
- Run dedicated power and ground from the house battery to the new amplifier location. Mount a fuse holder as close to the battery as possible. Leave the fuse out.
- Land power and ground to the new amplifier. Verify no wire strands are crossing or capable of contacting adjacent terminals.
- Final check. Confirm all connections are secure and wiring is routed cleanly. Install the battery fuse and restore power to test.
Section 3 — PNP Amplifier Rack Packages: Wetsounds / Hertz
Pre-assembled rack — full replacement of factory amplifiers in OEM location
Where's your factory amp?
- On Wet Sounds / Hertz-equipped Yamaha boats, the factory amp is on the back of the bow seat.
Recommended Installation Tools
| Tool | Notes |
|---|---|
| Adhesive-Lined Heat Shrink | Assorted sizes. Use adhesive-lined (dual-wall) tubing for a waterproof seal on all exposed connections. |
| Tape Assortment | Exterior-grade Tesa tape for wire bundling and harness protection; electrical tape for general insulation. |
| Zip Ties | Assorted sizes for securing wire runs and harnesses away from moving parts and heat sources. |
| Wire Strippers | For preparing speaker wire and any additional signal or power leads. |
| Fish Tape / Pull Rod | Required when routing wire through towers or to subwoofer locations. A flexible fiberglass rod works best in tight boat cavities. |
| Insulated Heat Shrink Butt Connectors & Spades | Use with a proper ratcheting crimper — never use non-ratcheting pliers. Match connector gauge to wire gauge. |
| Ratcheting Crimper | Ensures a consistent, full crimp every time. Required for reliable connections. |
| Heat Gun or Torch | For activating adhesive-lined heat shrink and properly sealing butt connectors. |
| #10 Screws | For securing amplifier racks to the seat-back bump-outs. Minimum of 4 screws recommended. |
| #8 Screws | For securing standalone (individual) amplifiers in their mounting location. |
| Standard Drill and Bits | For pilot holes before driving mounting screws. Prevents substrate cracking. |
| Torx and Allen Bits | Required for fuse holder terminals and power distribution block terminal screws — check your specific hardware before starting. |
Recommended Installation Materials
Always use tinned OFC (Oxygen-Free Copper) speaker wire. Do not use CCA (Copper-Clad Aluminum) — CCA wire has higher resistance and degrades faster in marine environments and can lead to premature failure.
| Application | Recommended Gauge | Wire Type |
|---|---|---|
| Additional speakers, 4-ohm subwoofers | 16 AWG | Tinned OFC |
| 2-ohm or lower subwoofers | 12 AWG | Tinned OFC |
Note
- Power and ground runs to any new amplifier must use proper marine-grade power wire sized for the amplifier's rated current draw. Run from the house battery with a fuse holder mounted as close to the battery as possible. Leave the fuse out until installation is fully complete.
The PNP Amplifier Rack Package integrates your new amplifier(s) onto a pre-built rack designed to mount directly where the factory amplifiers were installed. All harness adapters are included in the package.
Note
- The rack mounts to the bump-outs on the seat-back behind the starboard bow seat, under the helm. These bump-outs are most easily visible when the carpet is pulled back.
- Use a minimum of 4 × #10 screws through the rack mounting tabs and into the seat-back bump-outs. Drill pilot holes first to prevent substrate cracking.
- Route all harnesses and wiring clear of the rack position before final installation to avoid pinching.
Channel Map
| Channels | Speaker Zone |
|---|---|
| 1 – 2 (cabin/bow amp) | Bow and cabin speakers |
| 3 – 4 (cabin/bow amp) | Rear swim platform speakers |
| 5 – 6 (cabin/bow amp) | Subwoofer (if applicable) |
| 1 – 2 (tower amp) | Tower speakers |
Installation Steps
- Power down completely. Turn the boat off and switch all battery switches off.
- Locate and remove all factory amplifiers (see "Where's your factory amp?" above). Unplug all harnesses from each factory amplifier and remove them.
- Run new power and ground from the house battery to the rack mounting location before the rack goes in — routing is much easier with the space open. Mount a fuse holder as close to the battery terminal as possible. Leave the fuse out.
- Route all harnesses and wiring out of the way so they will not be pinched or obstructed when the rack is set into position.
- Set the amplifier rack into position. Align the rack with the seat-back bump-outs and verify fit before drilling.
- Secure the rack. Drill pilot holes, then drive a minimum of 4 × #10 screws through the rack mounting tabs and into the seat-back bump-outs.
- Adapt all harnesses. Plug each supplied adapter harness into its corresponding factory boat harness. Each connector is keyed to its mating plug. Refer to the channel map above for zone assignments.
- For additionally specified speakers (tower speakers, subwoofers): speaker wire whips will exit the amplifier or rack. Run speaker wire from each speaker location to the rack. Crimp appropriate spades onto the wire ends and adapt into the corresponding whips.
- Land power and ground to the rack. Verify no wire strands are crossing or capable of contacting adjacent terminals. Torque all terminal screws securely.
- Final check. Confirm all harness connections are fully seated and all wiring is routed away from moving parts and heat sources. Install the battery fuse and restore power to test.
Section 4 — PNP Amplifier Rack Packages: Aquatic AV
Rack or standalone amplifier — full replacement of factory amp
Recommended Installation Tools
| Tool | Notes |
|---|---|
| Adhesive-Lined Heat Shrink | Assorted sizes. Use adhesive-lined (dual-wall) tubing for a waterproof seal on all exposed connections. |
| Tape Assortment | Exterior-grade Tesa tape for wire bundling and harness protection; electrical tape for general insulation. |
| Zip Ties | Assorted sizes for securing wire runs and harnesses away from moving parts and heat sources. |
| Wire Strippers | For preparing speaker wire and any additional signal or power leads. |
| Fish Tape / Pull Rod | Required when routing wire through towers or to subwoofer locations. A flexible fiberglass rod works best in tight boat cavities. |
| Insulated Heat Shrink Butt Connectors & Spades | Use with a proper ratcheting crimper — never use non-ratcheting pliers. Match connector gauge to wire gauge. |
| Ratcheting Crimper | Ensures a consistent, full crimp every time. Required for reliable connections. |
| Heat Gun or Torch | For activating adhesive-lined heat shrink and properly sealing butt connectors. |
| #10 Screws | For securing amplifier racks to the seat-back bump-outs. Minimum of 4 screws recommended. |
| #8 Screws | For securing standalone (individual) amplifiers in their mounting location. |
| Standard Drill and Bits | For pilot holes before driving mounting screws. Prevents substrate cracking. |
| Torx and Allen Bits | Required for fuse holder terminals and power distribution block terminal screws — check your specific hardware before starting. |
Recommended Installation Materials
Always use tinned OFC (Oxygen-Free Copper) speaker wire. Do not use CCA (Copper-Clad Aluminum) — CCA wire has higher resistance and degrades faster in marine environments and can lead to premature failure.
| Application | Recommended Gauge | Wire Type |
|---|---|---|
| Additional speakers, 4-ohm subwoofers | 16 AWG | Tinned OFC |
| 2-ohm or lower subwoofers | 12 AWG | Tinned OFC |
Note
- Power and ground runs to any new amplifier must use proper marine-grade power wire sized for the amplifier's rated current draw. Run from the house battery with a fuse holder mounted as close to the battery as possible. Leave the fuse out until installation is fully complete.
Aquatic AV rack and amplifier packages are sized based on the amplifier model selected at time of purchase. Review the placement guidance below before beginning.
| Amplifier / Configuration | Recommended Mounting Location |
|---|---|
| Single amplifiers: AD800.4, AD1400.6, PXA1000.5, PXA400.4, and similar compact units | Stock amplifier location under the helm — direct replacement, use existing mounting points with #8 screws |
| Amplifier racks and multi-amplifier setups | Seat-back bump-outs behind the starboard bow seat, under the helm. Pull carpet back for best access. Use #10 screws, minimum 4. |
AR250 note
- AR250: the factory Aquatic AV amp is in the driver's helm cubby beneath the steering wheel. The cubby usually fits one 5 or 6 channel amp (a second amp can sometimes mount on the bottom left face of the cubby). Amp racks mount on the back of the bow seat instead, so AR250 rack installs need the extension option on our Yamaha Aquatic AV (AAV) Amp Harness: at least 5 ft ($10 per foot) to reach.
Channel Map
| Channels | Speaker Zone |
|---|---|
| 1–2 | Bow and cabin speakers |
| 3–4 | Rear swim platform speakers |
Installation Steps
- Power down completely. Turn the boat off and switch all battery switches off.
- Locate the factory Aquatic AV amplifier under the helm near the steering wheel. Unplug both factory harnesses and uninstall the amplifier.
- Determine your mounting location per the placement table above. If mounting to the seat-back bump-outs, pulling back the carpet will make them clearly visible.
- Run new power and ground from the house battery to the intended mounting location before securing the rack or amplifier. Mount a fuse holder as close to the battery terminal as possible. Leave the fuse out.
- Install the amplifier or amplifier rack. For seat-back installations: drill pilot holes and drive a minimum of 4 × #10 screws into the bump-outs. For helm replacements: use #8 screws into existing mounting points.
- Adapt the two supplied harnesses into the two stock boat harnesses unplugged in Step 2. The connectors are different — correct installation is not possible to get wrong. Channels 1–2 = bow and cabin; channels 3–4 = swim platform.
- For additionally specified speakers (tower speakers, subwoofers): speaker wire whips will exit the amplifier or rack. Run speaker wire from each speaker location to the amplifier. Crimp appropriate spades onto the wire ends and adapt into the corresponding whips.
- Land power and ground to the amplifier / rack. Verify no wire strands are crossing or capable of contacting adjacent terminals. Torque all terminal screws securely.
- Final check. Confirm all harness connections are fully seated and all wiring is routed cleanly away from moving parts and heat sources. Install the battery fuse and restore power to test.
Need Help?
If you have questions about your specific kit, boat model year, or amplifier configuration, reach out to Boat Harnesses before or during your installation. Having your boat model year, trim level, and amplifier brand on hand will help us get you sorted quickly.
⚠ Safety warnings
- Always confirm the boat is fully powered off and all battery switches are off before beginning or resuming any electrical work.
- The battery fuse must be the absolute last thing installed — after all wiring is landed, secured, and verified.
Need help with your install? Contact us.
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