Garmin GPSMAP 376C Manual

The Garmin GPSMAP 376C is a versatile color chartplotter and GPS receiver designed for marine and aviation use. It features a high-resolution color TFT display, built-in worldwide basemap, support for BlueChart and MapSource cartography, XM Satellite Weather and Radio capability (with optional subscription), WAAS-enabled GPS receiver, sonar interface (with optional transducer), NMEA 0183 interface, and rugged, waterproof construction. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: High-brightness color TFT display, GPS antenna, Power/data connector, XM antenna connector, External speaker jack, Card slot for data cards.

Feature	Description
Display	3.8-inch diagonal, 256-color TFT, 320 x 240 pixels
GPS Receiver	12 parallel channel, WAAS enabled
XM Satellite Ready	Weather and audio (subscription required)
Chartplotting	Supports BlueChart and MapSource detailed maps
Sonar Interface	Accepts optional GSD 20/21 sounder module
Waterproof Rating	IPX7 (submersible 1 meter for 30 minutes)
Power Input	10-40 VDC
Data Card Slot	Accepts Garmin data cards for maps and waypoints
NMEA 0183 Interface	For connection to autopilots, instruments, etc.
Backlit Keypad & Display	Adjustable for night operation

Installation

Unpack and inspect contents. Choose a suitable mounting location with clear view of sky for GPS.

1. Mounting: Use included bracket to mount unit on dash or console. Ensure secure fit.
2. Power Connection: Connect red wire to positive (+) DC source (10-40V). Connect black wire to negative (-) or ground.
3. Antenna Connection: Internal GPS antenna requires no external connection. For XM, connect optional XM antenna to dedicated port.
4. Data Connections: Connect NMEA 0183 wires to compatible devices if needed.

WARNING! Ensure all power is OFF during installation. Route cables away from moving parts and heat sources.

First-Time Setup

Power on unit; follow initial prompts.

1. Acquire Satellite Signal: Place unit outdoors with clear sky view. Allow several minutes for initial fix.
2. Set Language/Units: Press MENU > Setup > System to set language, units (nautical, statute), time format.
3. Calibrate Compass (if applicable): Follow on-screen prompts if using magnetic compass data.
4. Load Maps: Insert Garmin data card with BlueChart or MapSource maps. Unit will auto-detect.
5. Configure XM (optional): Enter XM activation code in XM Weather menu to enable service.

CAUTION! Do not operate while driving or piloting. Familiarize yourself with controls while stationary.

Specifications

• Display: 3.8" diagonal, 256-color TFT, 320 x 240 pixels.
• GPS: 12 parallel channel, WAAS enabled, position accuracy < 3 meters.
• Map Storage: Internal basemap, expandable via data cards.
• XM Satellite: Requires GXM 30 antenna and subscription for weather/audio.
• Interfaces: NMEA 0183, sonar (via GSD 20/21), data card, XM antenna.
• Power: 10-40 VDC, typical current draw 1.5A at 12V.
• Waterproof: IPX7 standard.
• Operating Temp: -15° to 70°C (5° to 158°F).
• Dimensions: 6.0" W x 4.2" H x 2.8" D (15.2 x 10.7 x 7.1 cm).

Controls and Settings

Front Panel: POWER key, ROCKER key (up/down/left/right/ENTER), PAGE key, MENU key, ZOOM IN/OUT keys, MARK key.

On-Screen Menus: Access via MENU key. Main pages: Map, Compass, Highway, Active Route, XM Weather, XM Radio, Sonar (if equipped).

Setup Categories: System (language, units, backlight), Navigation (routing preferences), Marine (alarms, tide data), XM (activation, audio settings), NMEA (interface settings).

Map Display Settings: Detail level, track line, waypoints, data fields.

Connecting Devices

NMEA 0183: Connect to autopilot, AIS, or other NMEA devices. Sonar: Connect optional GSD 20/21 sounder module. XM: Connect GXM 30 antenna.

1. Turn off power to all devices.
2. Refer to wiring diagrams in Appendix for NMEA pinouts.
3. Secure all connections with appropriate terminals; protect from moisture.
4. Configure NMEA sentences in Setup > Interface menu.

Tip: Use marine-grade heat-shrink connectors for all splices in marine environments.

Using GPS Navigation

Create and follow routes, mark waypoints, track your path.

1. Go To a Point: Press FIND, select Waypoints, Cities, etc. Select destination, press ENTER > Go To.
2. Create a Route: Press MENU from Map page > Route > New Route. Add points from map or waypoint list.
3. Follow a Route: Select route from Route list, press MENU > Navigate.
4. Mark a Waypoint: Press and hold MARK key at desired location. Edit name/symbol if needed.
5. View Data Pages: Press PAGE to cycle through Map, Compass, Highway, Active Route pages.
6. Set a MOB (Man Overboard): Press and hold MARK key twice quickly. Creates a route back to marked position.

WARNING! GPS is an aid to navigation. Always use in conjunction with official charts and prudent seamanship/airmanship.

XM Satellite Features

With optional GXM 30 antenna and active subscription.

XM Weather: View NEXRAD radar, satellite imagery, lightning strikes, forecasts, sea surface temps. Access via XM Weather page.

XM Radio: Listen to commercial-free music, news, sports. Access via XM Radio page. Use rocker key to change channels.

Activation: Requires purchase of XM subscription. Enter activation code in Setup > XM > Subscription menu.

Care & Cleaning

Disconnect power before cleaning. Use a soft, damp cloth with mild soap solution. Do not use abrasive cleaners or solvents.

CAUTION! Ensure connectors are dry before reconnecting power. Do not submerge unit while connected to power.

Regulatory Information

FCC Part 15: Class B digital device. Complies with Canadian ICES-003. Contains GPS receiver regulated under FCC Part 15. XM service governed by XM Satellite Radio agreements. Copyright © Garmin Ltd. or its subsidiaries. For support, visit www.garmin.com/support or contact Garmin Product Support.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Blown fuse, loose connection	Check fuse (3A) in power cable. Verify secure connections at unit and power source.
Poor GPS reception	Obstructed view of sky	Relocate unit or antenna for clear view. Ensure no metal obstructions overhead.
XM signal lost	Antenna obstruction, subscription lapsed	Ensure XM antenna has clear southern view (continental US). Verify active subscription.
Map not displaying	Data card not seated, corrupt data	Reinsert data card firmly. Try a different, known-good data card.
Unit freezes	Software issue	Perform soft reset (disconnect power for 30 seconds). As last resort, perform master reset (see manual, erases user data).
NMEA data not received	Incorrect wiring or settings	Verify wiring per diagram. Check NMEA baud rate matches connected device (usually 4800).

Reset: Setup > System > Reset to factory defaults (erases all user data).

Service: Contact Garmin Product Support. Do not open unit; voids warranty.