# Wire guage for Fishfinder



## britcom61 (Sep 6, 2012)

Can anyone tell me if the wire guage for the power supply line makes any difference when it needs to be extended? I bought a trolling motor transducer kit, and the power line is only 4ft long, I need 12ft. If I use light weight speaker wire, will that cause a problem or should I use something heavier than the original power supply line. Seems like a no-brainer, but I'm recarpeting the complete boat and the power supply needs to be put behind the side pannel. Once in place it wioll be hard to change, so I want it right! Thanks.....


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## RivRunR (Sep 7, 2012)

I'm confused....you say you got a TM transducer mounting kit with a 4' power lead, but transducers don't have power leads and typically run on cable, so I'm guessing that you're moving the fish finder up front?

Any any case, speaker wire is a BAD idea in a boat.

If you're moving the fish finder and need to extend the power lead, use tinned marine wire. 14AWG should be fine, 12AWG would be better. And fuse it within 7" of the battery.


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## russ010 (Sep 7, 2012)

here's my general rule of thumb for electronics...

Trolling Motor - most have 8-10ga wire. Go as big as you can and wire the TM straight to the battery or a 40-50amp fuse depending on the motor. I use no less than 4ga wire, and usually go to a dual bus bar, then hook the TM to that... - https://shop.genuinedealz.com/Items/2017?&caSKU=2017&caTitle=Blue%20Sea%202017%20Power%20Post%202x3/8in%20Studs ... I don't like running any electronics on that line, I leave it strictly for the TM, and I run a separate battery for all electronics.

If I have to mount electronics up at the front, I'll run a separate power wire up to the front to a distribution block. The main line I run is usually 10ga, and I'll run a negative as well. From that block, I'll run 14ga to whatever electronics - lights, radio, bilge & livewell pumps, radio, fish finders, etc. Here is the type distribution block I run - https://www.ebay.com/itm/MARINE-ELECTRICAL-PRODUCTS-10-POSITION-BOAT-FUSE-BLOCK-/190640255526?forcev4exp=true


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## krawler (Sep 11, 2012)

Most fish finders draw less than 3 amps and manufactures use 20 gauge wire most of the time. 18 gauge wire would be the best choice and 14 gauge would work just fine but its overkill.


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