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Quick Answer
Every fish finder brand uses its own transducer plugs. Garmin uses 4-pin, 8-pin and 12-pin plugs, Humminbird uses 7-pin and 14-pin plugs on its current ranges, and Lowrance and Simrad use a 7-pin blue plug on older units and a 9-pin plug on newer ones. Count the pins, note the brand, and check the transducer's full part number. An adapter cable can change the plug, but it only works if the fish finder also supports the transducer's sonar.
Who This Guide Is For
This guide helps you if you are matching a transducer to a fish finder, buying an adapter or extension cable, or checking a used transducer before you buy it.
It will not help with wiring diagrams, splicing cut cables or repairing damaged plugs. For those, contact the manufacturer or a marine electronics installer.
How to Tell Connectors Apart
You can identify most transducer plugs with five checks, in this order.
| Check | What to look for | Why it matters |
|---|---|---|
| Brand | The fish finder brand the plug was made for | Plugs are brand-specific, though another company may have made the transducer |
| Pin count | The number of pin positions in the plug face | Separates plug families within a brand, such as Garmin 4-pin, 8-pin and 12-pin |
| Colour | Some plugs are colour-coded | Airmar lists the Garmin 8-pin plug as blue, the Garmin 12-pin as orange and the Lowrance/Simrad 7-pin as blue |
| Model number | The part number on the cable label | Confirms the exact transducer, and with Humminbird the number in the name hints at the plug |
| Adapter support | Whether the brand sells an adapter for your pair | Shows whether two plug families can be joined, and which features survive |
Airmar notes that some connectors do not use every pin position, so treat the pin count as the size of the plug, not the number of wires inside it.
Connectors by Brand
| Brand | Plugs | What they fit | Notes |
|---|---|---|---|
| Garmin | 4-pin, 8-pin (blue), 12-pin (orange), and 6-pin for depth, speed and temperature | Garmin units with the matching sonar port. Many ECHOMAP and GPSMAP units have a 12-pin transducer port | Garmin sells adapters such as 4-pin transducer to 12-pin unit (010-12718-00). Its 12-pin adapter connects 12-pin, 8-pin, 6-pin and bare-wire transducers, but water speed wheels are not supported through the 12-pin sounder connector |
| Humminbird | 7-pin and 14-pin, plus 21-pin and #9 plugs on some models | Transducers with a 9 in the model name (XNT 9, XM 9, XTM 9, XP 9) fit HELIX and older 300 to 1100 series units. Transducers with a 14 in the name fit APEX, SOLIX, ONIX and ION units | Humminbird sells 7-pin and 14-pin extension cables and Y-cables for each family. ION and some ONIX units need the Sonar Module |
| Lowrance and Simrad | 7-pin blue on older units, Navico 9-pin on newer units | Units with the matching sonar port | Lowrance sells adapters between the two, such as 000-12571-001, which connects a 9-pin XSONIC transducer (with analog temperature and no XID) to a legacy 7-pin blue unit plug. Simrad also used a separate JRC/Simrad 7-pin plug |
| Raymarine | 11-pin and 6/9-pin, plus DSM, ST50 and ST60 plugs | Raymarine units with the matching port | Check the exact unit and transducer part numbers with Raymarine before buying |
| Minn Kota built-in | 4-pin and 14-pin sonar cables, plus an 8-pin cable that is not for sonar | Humminbird units directly, other brands through Minn Kota adapter cables | A 4-pin cable is Universal Sonar 2. A 14-pin cable is MEGA Imaging or Dual Spectrum CHIRP. On 2023 and newer motors, adapter cables come in the box, SOLIX units need none and HELIX units need one |
How to Match a Plug to Your Fish Finder
- Switch the fish finder off and unplug the transducer.
- Note the fish finder's brand and full model, including any generation code such as G3N or G4N.
- Look at the sonar port on the back of the unit. Many manuals label it, for example Garmin's ECHOMAP Ultra manual lists a "12 PIN XDCR" port.
- Count the pins on the transducer plug and note its colour.
- Read the part number on the transducer cable label. Our guide on how to identify your transducer model number shows where to find it.
- Compare the plug family with the table above. If they match, check the transducer is supported by your unit.
- If they do not match, look for a manufacturer adapter for that exact pair, and read what it supports.
- Confirm with the manufacturer before buying a transducer or adapter you have not seen listed for your unit.
Worked example
Buying a replacement transducer for a Humminbird HELIX
You own a Humminbird HELIX and find a used Humminbird transducer listed as an XNT 14 model. Will it plug in?
- Identify your plug family. Humminbird's accessory guide matches HELIX units with transducers that have a 9 in the model name, which use the 7-pin plug.
- Read the listing. The transducer has a 14 in the model name, which Humminbird matches to APEX, SOLIX, ONIX and ION units.
- Compare. The plug families do not match, so it will not plug straight into your HELIX.
- Find the right family. Search for the equivalent model with a 9 in the name, then check it is listed as compatible with your exact HELIX model and generation.
- Result. You avoid buying a transducer that does not fit, and you know which model family to look for instead.
When an Adapter Is Not the Answer
- The plug fits but the sonar does not. A traditional 2D transducer on an adapter will not give you side imaging, and the fish finder must support the transducer's frequencies.
- Some features drop out. Garmin's 12-pin adapter instructions say water speed wheels are not supported through the 12-pin sounder connector.
- The adapter is only listed for some units. Garmin's 4-pin to 12-pin adapter is listed for compatible ECHOMAP and GPSMAP devices, not every Garmin unit.
- Older plugs may have no adapter at all. Check that a manufacturer adapter exists for your exact pair before you buy.
- Third-party transducers can carry any brand's plug. A transducer made by Airmar can be fitted with a Garmin, Humminbird or Lowrance plug, so always check the part number rather than the plug alone.
Action Checklist
This page contains no affiliate links. It was researched from the manufacturer and supplier documents listed below, and the products were not tested by us. We will recheck it by May 2027, or sooner if Garmin, Humminbird, Lowrance, Simrad or Minn Kota release a new connector type.
Common Questions
Do all fish finder brands use the same transducer plug?
No. Each brand uses its own plugs, and most have changed them over the years. Airmar's connector guide lists more than 20 different brand connectors.
Is the pin count the same as the number of wires?
Not always. Airmar notes that some connectors do not use every pin position, so the pin count is the connector's size, not a wire count.
Which plug does a Humminbird HELIX use?
Humminbird's accessory guide matches transducers with a 9 in the model name, such as XNT 9 or XM 9, to HELIX units, and transducers with a 14 in the name to APEX, SOLIX, ONIX and ION units.
Can I convert a Garmin 4-pin transducer to a 12-pin fish finder?
Garmin sells an adapter for this, part 010-12718-00, for compatible ECHOMAP and GPSMAP units. Check that your unit is listed and that the sonar features you want are supported before buying.
Does an adapter cable make any transducer work with any fish finder?
No. An adapter changes the plug, but the transducer's sonar type and frequencies must also be supported by the fish finder.
Sources
- Airmar Connector Guide
- Garmin 12-pin Transducer Adapter installation instructions
- Garmin ECHOMAP Ultra owner's manual, Connector View
- Garmin 4-pin transducer to 12-pin sounder adapter 010-12718-00, retailer listing
- Humminbird Accessory Resource Guide (PDF)
- Humminbird Help Center, How to Identify Your Transducer
- Lowrance 9-pin to 7-pin adapter cable 000-12571-001, retailer listing
- Minn Kota Help Center, Identifying the Cables Coming from Your Motor
Manufacturers change part numbers and firmware support. Confirm with the manufacturer before you buy.