GPSMap 943xsv
Garmin GPSMAP 943xsv wiring diagram
Power the Garmin GPSMAP 943xsv through its dedicated DC harness, even when NMEA 2000 is connected. See the power wires, 6 A fuse and separate network requirements.
- Compatible systems
- 12 V / 24 V
- Maximum draw at 12 V
- 3.2 A
Connection essentials
Dedicated power harness
Red connects to positive; black to negative. The chartplotter accepts 10–32 V DC.
Keep the 6 A fuse
The 9x3 model specifies a 6 A, 125 V fast-acting fuse. Use the model-specific rating.
Network power is separate
NMEA 2000 does not supply the chartplotter. Check existing backbone power before adding a feed.
Wiring diagram
How the Chartplotter is wired.
The drawing covers the dedicated DC power feed. NMEA 2000, Garmin Marine Network and transducer connections are not shown.
The GPSMAP 943xsv example retains the 9x3 model's 6 A fast-acting fuse and uses its 3.2 A maximum at 12 V as the design current. Preserve the supplied harness protection. Power extensions need their own cable and source-protection review; NMEA 2000 does not power the chartplotter. Manufacturer installation manual
Edit this wiring exampleChartplotter power-supply sizing
This 12 V example shows the dedicated power harness with the model-specific fuse. Network and sonar connections need separate planning.
3 m one way
12 V system
- Wire
- 1.5 mm² · 16 AWG
- Example fuse
- 6 A
- Design current
- 3.2 A
- Voltage drop
- 1.9%
Sized against ABYC E-11. The design current is the part's continuous draw. The length is one way; voltage drop includes an equal-length return.
Run-length and manufacturer assumptions
The editable example uses 3.048 m (10 ft) runs unless a shorter run is stated. Metric overviews round these to 3 m. Adapt the parts and lengths to your installation before choosing cable and protection.
The GPSMAP 943xsv example retains the 9x3 model's 6 A fast-acting fuse and uses its 3.2 A maximum at 12 V as the design current. Preserve the supplied harness protection. Power extensions need their own cable and source-protection review; NMEA 2000 does not power the chartplotter. Manufacturer installation manual
Supporting parts
- 6.1 m total of 1.5 mm² (16 AWG) marine cable
- Terminations for 1.5 mm² cable, matched to the equipment's screw terminals, leads or studs
- 6 A fuse and holder on the positive run
- Heat-shrink, strain relief and terminal boots sized to the cable
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Verified against the manufacturer's documentation (rev. GUID-BF2FF273-008A-482A-A96F-362ADA8996BA v8 — January 2025), checked 2026-10-12. Manufacturer documentation →
How much power does the GPSMAP 943xsv use?
This guide covers the Garmin GPSMAP 943xsv, the sonar-equipped 9-inch model. Garmin lists 1.37 A typical and 3.2 A maximum at 12 V. Use the GPSMAP 9x3 sonar rows in the installation specifications, page 20 for the full ratings, including 40.2 W maximum at 10 V. The 22 W and 1.78 A figures alongside them apply to the non-sonar version. Crimp uses 3.2 A as the circuit-sizing default. Typical current is useful for an energy budget; maximum current matters when assessing the supply circuit.
Can I use a 24 V system, and how do I budget energy?
The family accepts 10–32 V DC, so the chartplotter's dedicated power input can run from a suitable 12 V or 24 V system. The canvas energy estimate also uses the fixed 3.2 A allowance; it is not typical consumption or a manufacturer-specified 24 V current. Use operating-voltage and measured or typical consumption data when assessing endurance. The sonar connector is for a compatible 12-pin transducer; the presence of that port does not establish compatibility with every transducer.
Which power wires and fuse should I use?
Garmin's power-harness instructions, pages 9–11 identify red as positive power and black as negative. The example retains the model-specific 6 A protection. Secure the connector’s locking ring and O-ring. The 9x3 specification is a 6 A, 125 V fast-acting fuse. The shared extension illustration labels an 8 A fuse; use the model-specific 9x3 rating rather than copying that larger value.
Choose power extensions by length and voltage drop. Do not use the manual's 22 AWG data/alarm-wire size for the power feed. The fuse must protect the installation as arranged, and an extended feed needs protection close to its source.
Does NMEA 2000 supply the chartplotter?
No. Garmin's network instructions, pages 12–13 require the dedicated power harness even when NMEA 2000 is connected. The backbone has its own power arrangement; identify existing network power before adding another feed. Garmin Marine Network devices also need a common power ground.
What should be checked before mounting?
The 9x3 has a 30 cm compass-safe distance. Test the viewing angle at the proposed location and leave access for cables and the rear memory-card slots. For flush mounting, use Garmin's template and supplied hardware; the display itself must not be used as a drilling template. Install the included ferrites on the power, transducer and USB cables as directed on page 18.
Fit check
Connect it to the rest of your system.
Describe your setup to draft a system with GPSMap 943xsv connected. Review the selected parts and cable lengths, then edit the diagram in Crimp.
The model only picks parts and draws the connections. Every wire size and fuse rating still comes from Crimp's own sizing, never from the model.
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Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
GPSMAP 943xsv 9-inch chartplotter with sonar: 1.37A typical and 3.20A maximum at 12V, with 40.2W maximum at 10V. Accepts 10–32V DC and uses a 6A fast-acting fuse. The dedicated power harness is required even when connected to NMEA 2000.
- Compatible systems
- 12 V / 24 V
- Maximum draw at 12 V
- 3.2 A
Terminal map
Positive and negative represent the dedicated power harness: red + and black −. The current values are planning allowances, not connector ratings. NMEA 2000, network, sonar and data wiring are not represented.
+
positive · input
−
negative · input
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Example sizing. Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
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