# Trolling Motor - going from 10ga to 6ga wire?



## hawkman (May 19, 2018)

So, I'm installing a used 12V 55# MK Powerdrive TM on my PF 17T. The former TM - a Motor Guide might have had 8ga connections. Somehow, under the deck, it appears it switches over to 6ga to the circuit breaker and battery.

The Powerdrive has 10ga wire coming from it. MK sells a quick-connect that is 10ga. 

What gives? What advantage do I have in keeping the 6 or 8 all the way to the motor where it switches to 10?

I was going to put in a new circuit breaker and run all 10gauge wire but heck - wire isn't free and the 6 gauge is already there. The circuit breaker (or fuse) is old and I don't know if it works. The old plug works fine but I'd have to go from 10ga to what looks like 6ga. That's a big jump to butt-connect. I've read in various places on how to (or not to) do this. One method is to melt off the plastic coating on a 6ga connector, fold over the 10ga so it is double-thick, crimp it all really well, and use one or more layers of shrink wrap over it.

Am I better off running new wire - all 10ga? Or figure out this multi-gauge connection? I don't foresee me needing a larger TM for this boat - but I'm not that experienced so I'm looking to you.


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## Charles Hadley (Jan 20, 2019)

Follow recommendations on minkota website for wiring and distance for your application for optimum performance of your trolling motor


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## Mdees88 (Jun 23, 2021)

Charles Hadley said:


> Follow recommendations on minkota website for wiring and distance for your application for optimum performance of your trolling motor


THIS ^^^

The *length of the circuit* and the current determines what wire size is needed. The longer the run the more voltage drop which means you need a bigger gauge wire. The reason the wires on the TM are 10ga are because they are only a few feet long. The reason you have 6 and 8ga wired in the boat is because it's a longer run between the batteries and the TM plug then the TM and the TM plug.

Larger trolling motors can actually use smaller wires because they operate at a higher voltage. A high thrust 12v TM requires a larger wire than a 36V TM.

If you want to use the plug you have already buy a 10 to 8 step down butt connecter and some heat shrink tubing. Step-Down Tinned Butt Splice

Personally I would do away with the quick disconnect and mount a blue seas system dual power post Dual PowerPost - Blue Sea Systems or feed through connectors depending or your setup. Feed Through Connectors - Blue Sea Systems Then all you need is 8ga ring terminals and 10ga ring terminals (no butt splices). This connection will never work loose and takes less than a minute to unhook the wires if you want to remove the TM.

If you're dead set on a quick disconnect battery tender makes solid unit that hasn't given me any trouble. Amazon.com: Battery Tender DC to DC Power Connector: Trolling Motor Plug for Onboard Marine 12V DC to DC Power Connection - Weather Resistant DC Plug with 80 AMP Capacity - 027-0004-KIT: Automotive. Takes ring terminals so no butt splices either.

I would recommend a blue sea system 285 series circuit breaker too if you haven't bought one yet. Whatever you get, do not buy the small grey and black breakers with the tiny black reset button on the side, they are garbage.


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## Steve_Mevers (Feb 8, 2013)

Hadley nailed it. Use some kind of block or Dual Post to connect your heavier wire to and trolling motor. If the heavier gauge wire is in good shape, just use it.


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## Gogittum (May 24, 2020)

The previous answers sound good, but I'm a little uncertain of what sequence of which size wires you have. Generally, the bigger the wire the better but "always" use the heavier gauge first. It sounds like your setup starts with 6 gauge, then down to 8 gauge and 10 gauge at the motor. Fine, but if there's 10 gauge at the beginning, that's not so good. If it really is 6 & 8 gauge from battery out, I'd use it rather than replace with 10 gauge.


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## hawkman (May 19, 2018)

Charles Hadley said:


> Follow recommendations on minkota website for wiring and distance for your application for optimum performance of your trolling motor


At first, I was taken aback by your post b/c I've often found manufacturers' websites to disappoint. However, MK has a decent page on wire gauge needed for different motors so I appreciate the tip.



Gogittum said:


> ...I'm a little uncertain of what sequence of which size wires you have...


My bad. After another look, I realized it's 6-gauge from the battery to the circuit breaker to the trolling motor plug (boat mounted, female end). The male end is also 6-gauge and is now connected to the 10-gauge coming directly out of the MK motor base. 

I got it connected last night and the motor runs so that's good.


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## kylet (Jun 29, 2017)

It’s a proportion deal, length and girth. Don’t want long and skinny nor do you want shirt and stubby.


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