Diamond Audio Stage 2 Installation Guide | 2015-2023 Road Glide

Diamond Audio Stage 2 Bundle Installation Guide

2015-2023 Harley-Davidson Road Glide

Before you begin, park the motorcycle on a stable surface and turn the ignition off.

Please note that your Road Glide will require some modifications prior to installation. Please review the video linked here for guidance on the required modifications before proceeding.

Tools Needed

• Plastic panel removal tool
• T25 Torx bit
• T27 Torx bit
• 3/16" Hex bit
• 1/8" Hex bit
• Ratchet wrench
• Fender cover or soft towel
• Heat gun
• Small flathead screwdriver
• Zip ties (recommended)

Step 1: Remove the Outer Fairing

1. Use a plastic panel removal tool to carefully remove both speaker grilles, starting near the handlebars.
2. Remove the T27 bolt located beside each speaker.
3. Remove the T27 bolt at the lower outer edge of the fairing on each side.
4. Remove the turn signal mounting screws using a 3/16" hex bit.
5. Cover the front fender with a towel or fender cover to protect the paint.
6. Remove the four windshield mounting screws using a 1/8" hex bit.
7. Remove the windshield.
8. Pull straight up on the fairing vent to release the retaining clips.
9. Disconnect any wiring attached to the outer fairing.
10. Carefully remove the outer fairing and set it aside.

Step 2: Remove the Factory Speakers

1. Remove the four T25 screws holding each factory speaker in place.
2. Disconnect the speaker wiring connectors.
3. Please watch the video linked here before you proceed with installation.
   1. Using a heat gun, gently warm the inside of each speaker pod.
   2. Once the plastic softens, remove the factory interior fins from the pod.

Tip: Keep the heat gun moving to avoid overheating the plastic.

Step 3: Install the Diamond Audio 6.5" Horn Speakers

1. Connect the supplied crossover to the speaker:
   • 1/4" connector to the 1/4" speaker terminal
   • 1/8" connector to the 1/8" speaker terminal
2. Connect the supplied speaker pigtail to the crossover by matching the wire colors:
   • Twist the red wires together
   • Twist the black wires together
3. Insert the red wires into the red push terminal.
4. Insert the black wires into the black push terminal.
5. Connect the pigtail to the factory speaker wiring.
6. Place the speaker into the speaker pod, aligning the mounting holes.
7. Install the speaker with the Diamond Audio logo upside down.
8. Warm the outside of the speaker pod with the heat gun to soften the plastic.
9. Install the supplied black Phillips-head screws.

Tip: Start all four screws by hand before tightening them completely.

Step 4: Remove the Factory Radio

1. Remove the two T25 screws securing the metal support bracket above the radio.
2. Disconnect all wiring connectors from the rear of the radio.
3. Press the release tabs before unplugging each connector.
4. Remove the four 3/16" hex bolts securing the radio.
5. Save these bolts, as they will be reused.
6. Lift the radio upward and forward to remove it.

Step 5: Mount the Amplifier

Choose one of the following mounting methods:

• Use the included Velcro squares.
• Use the included Velcro sheet.
• Drill mounting holes and secure the amplifier with screws.

Step 6: Install the Amplifier Mounting Plate

1. Remove the four T25 screws from the fairing support plate.
2. Position the supplied amplifier bracket beneath the support plate.
3. Make sure the bracket lip slides over the rear crossbar.
4. Align all four mounting holes.
5. Install the supplied nuts and bolts.

Tip: Start all hardware by hand before tightening.

Step 7: Reinstall the Radio

1. Place the radio back into its factory location.
2. Loosely install the four original 3/16" mounting bolts.
3. Connect the factory USB cable.
4. Connect the AM/FM antenna.

Do not fully tighten the radio yet.

Step 8: Install the MSTLINK Harness

Factory Radio Installation

1. Unplug the factory male connector from the rear of the radio.
2. Connect the female MSTLINK connector to the motorcycle's factory wiring harness.
3. Connect the Front Left and Front Right RCA Molex connector to the amplifier's Front Input.
4. Connect the White and Gray wire Molex connector to the Front Output.

VOX Turn-On Option: The amplifier can be set to signal-sensing mode. The amplifier may remain on for 30–60 seconds after the motorcycle is turned off.

Remote Turn-On Option:

1. Connect the blue wire 2-pin white connector to the matching black factory connector near the clutch-side speaker pod.
2. Connect the larger black connector with the yellow, blue, and black wires to the matching connector on the wiring harness.
3. Connect the wire labeled Accessory+ to the amplifier REM terminal and tighten using a 2mm Allen wrench.

Step 9: Run the Power and Ground Wires

Remove the Seat and Fuel Tank

1. Remove the seat.
2. Remove the ECU plate above the battery using the T40 bolts.
3. Disconnect the ECU connectors.
4. Remove the front and rear fuel tank mounting bolts.
5. Disconnect the fuel line and vent hoses.
6. Carefully remove the fuel tank.

Note: Keep a towel nearby to catch any fuel drips.

Route the Wiring

1. Open the wire chase cover.
2. Remove the 60-amp fuse from the inline fuse holder.
3. Route the power and ground wires through the wire chase.
4. Route the wires up the clutch side of the motorcycle into the fairing.
5. Connect the red wire to the amplifier's 12V input.
6. Connect the black wire to the amplifier's Ground terminal.
7. Connect the ring terminals to the battery.
8. Reinstall the 60-amp fuse.
9. Secure all wiring with zip ties.

Step 10: Set the Amplifier Gain

1. Turn the motorcycle ignition on.
2. Play music that will run continuously for several minutes.
3. Set the radio volume to approximately 75% of maximum.
4. Use a small flathead screwdriver to adjust the Front Gain control.
5. Increase the gain until the desired volume level is reached.
6. Make any additional sound adjustments using the radio's EQ settings.

Important: Avoid setting the gain too high, as this can cause speaker distortion.

Step 11: Reassemble the Fairing

1. Reinstall the radio support bracket with the curved side facing upward.
2. Position the outer fairing.
3. Temporarily install one windshield screw to hold the fairing in place.
4. Reconnect all wiring.
5. Reinstall the turn signal mounting screws.
6. Install the fairing vent.
7. Reinstall the windshield and mounting hardware.
8. Reinstall all T27 fairing bolts.
9. Snap the speaker grilles back into place.

Final Inspection

• Verify all wiring connections are secure.
• Confirm battery connections are tight.
• Ensure the amplifier powers on properly.
• Verify both speakers are operating correctly.
• Confirm all fairing and windshield hardware is tightened.

Your Diamond Audio Stage 2 Bundle installation is now complete!