MB Quart GMR-3 Gauge Mount Radio User Manual

1. Introduction

This manual provides detailed instructions for the installation, operation, and maintenance of your MB Quart GMR-3 Bluetooth AM/FM Gauge Mount Radio. Please read this manual thoroughly before using the product to ensure proper function and safety. The GMR-3 is designed for marine and powersports applications, offering robust performance in challenging environments.

2. Safety Information

Always observe the following safety precautions to prevent injury or damage to the unit:

• Ensure all wiring is correctly connected to prevent short circuits or electrical hazards.
• Do not attempt to disassemble or modify the unit. Refer all servicing to qualified personnel.
• This product is designed to be waterproof and dustproof; however, avoid high-pressure water jets directly on the unit.
• Proposition 65 Warning: This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

3. Package Contents

Verify that all items are present in the package:

• MB Quart GMR-3 Audio Source Unit
• Mounting Hardware (screws, bracket)
• Wiring Harness
• User Manual (this document)

4. Installation

The GMR-3 is designed for gauge-style mounting. Professional installation is recommended.

4.1 Mounting the Unit

1. Choose a suitable location on your dashboard or panel that allows for a 3-inch diameter mounting hole.
2. Ensure there is sufficient depth (approximately 4.1 inches) behind the panel for the unit and wiring.
3. Cut a 3-inch (76mm) diameter hole using an appropriate hole saw.
4. Insert the GMR-3 unit into the opening.
5. Secure the unit using the supplied mounting bracket and hardware. Tighten securely but do not overtighten.

4.2 Wiring Connections

Refer to the wiring diagram provided with your unit for specific connections. General connections include:

• Power: Connect the yellow wire to a constant 12V power source, the red wire to a switched 12V accessory power source, and the black wire to ground.
• Speakers: Connect speaker wires to the appropriate positive and negative terminals. The unit supports a minimum impedance of 4 ohms.
• Pre-Amp Outputs: Utilize the 2 pairs (Front/Rear) of 4V pre-amp outputs for connecting external amplifiers.
• Antenna: Connect your AM/FM antenna.

Image: The MB Quart GMR-3 unit seamlessly installed into a vehicle's dashboard, demonstrating its compact gauge-mount design.

5. Operating Instructions

The GMR-3 features a user-friendly interface with large, waterproof buttons designed for easy operation, even with gloves.

Image: A detailed diagram of the MB Quart GMR-3 unit, highlighting the functions of its various buttons including Power, Volume Up/Down, Mode, and Band/Track controls.

5.1 Power On/Off

Press the POWER button located at the top of the unit to turn the radio on or off.

5.2 Source Selection

Press the MODE button to cycle through available audio sources: AM, FM, Bluetooth, RCA (Auxiliary Input), and USB.

5.3 Volume Control

Use the + VOL and - VOL buttons to adjust the audio output level.

5.4 Bluetooth Operation

1. Select Bluetooth mode using the MODE button. The display will show 'BT MUSIC'.
2. On your mobile device, search for Bluetooth devices and select 'MB Quart GMR-3'.
3. Once paired, the unit will automatically connect to the last paired device when in range.
4. Use the BAND / ◀◀ and ▶▶ buttons to skip tracks forward or backward.

5.5 AM/FM Radio

1. Select AM or FM mode using the MODE button.
2. Press the BAND button to switch between FM bands (FM1, FM2, FM3) or AM bands (AM1, AM2).
3. Press and hold the ◀◀ or ▶▶ buttons to seek for the next strong station.
4. Briefly press the ◀◀ or ▶▶ buttons to manually tune the frequency.

5.6 Apple Control

The GMR-3 features Apple Control, allowing quick access and navigation of your iTunes collection when an Apple device is connected via USB.

6. Maintenance

To ensure the longevity and optimal performance of your GMR-3 radio, follow these maintenance guidelines:

• Cleaning: Use a soft, damp cloth to clean the unit's surface. Avoid abrasive cleaners or solvents.
• Protection: While the unit is designed to be waterproof, dustproof, and UV stable (Life Shield), avoid prolonged exposure to extreme conditions or direct high-pressure water spray.
• Connections: Periodically check all wiring connections to ensure they are secure and free from corrosion.

7. Troubleshooting

If you encounter issues with your GMR-3, refer to the following common problems and solutions:

• No Power:
  • Check all power connections (constant 12V, switched 12V, ground).
  • Verify the vehicle's battery voltage.
  • Check for blown fuses in the power circuit.
• No Sound:
  • Ensure the volume is turned up.
  • Check speaker connections for proper polarity and secure contact.
  • Verify that the correct audio source is selected.
  • If using external amplifiers, check their power and signal connections.
• Bluetooth Not Connecting:
  • Ensure the GMR-3 is in Bluetooth mode.
  • Make sure Bluetooth is enabled on your mobile device.
  • Delete 'MB Quart GMR-3' from your device's paired list and attempt to re-pair.
  • Move your device closer to the GMR-3 (Bluetooth range is approximately 32 feet / 10 meters).
• Display Issues (e.g., condensation):
  • While the unit is designed for marine environments, extreme temperature changes can sometimes cause temporary condensation. Allow the unit to acclimate to ambient temperature.
  • If the issue persists, contact customer support.

8. Specifications

9. Warranty and Support

MB Quart products are manufactured to high-quality standards. For warranty information and customer support, please refer to the warranty card included with your product or visit the official MB Quart website. Keep your proof of purchase for warranty claims.