wiring questions for my new trolling motor

[H-SCbassman]

Well, after battling with my old trolling motor for way too long, I decided to go out and get a new one yesterday. I got the minn kota powerdrive 55 (12v, 50amps?). Now I just have a few questions about wiring.

First, this is going on my 14ft jon boat. The tm is up front and the battery is in the back. I am following the recommendation that I found on the motor that said to run 6 gauge wire. Now for my first question. On my old trolling motor, I used one of those male/female plugs in the front of the boat so that I could disconnect the tm if I wanted to. I would like to do the same with this tm if possible; however, all of the plugs that I am finding only have 10 gauge wire on them, so I was wondering if there would be a problem if I hooked the plug with the 10 gauge wire to the 6 gauge wire that I am running down the boat. I've looked all over the place (gander mountain, bass pro shop, west marine) and I cant find any of these plugs with thicker wire.  

All right, so my next question has to do with fuses. Minn kota recommends using a "50 amp manual reset breaker." Again, I have looked all over the place and cant find this either. At gander mountain, I found a 50 amp automatic reset breaker, and I was wondering if that would work ok, or do I really need a manual reset breaker. Also, at radioshack I found an inline fuse holder that uses the AGU type fuses (looks like a tube). It says that it is waterproof and can be used in marine applications, and it has a rating of up to 100 amps, so I was thinking about using that unless ya'll dont think thats a good idea.

And finally, my last question. On a little sticker on the trolling motor minn kota recommends that the battery that the trolling motor is hooked up to should be used only for the trolling motor. This presents a problem, because I carry only one battery on my boat, and previously I was using it to run my depth finder and trolling motor. Will it be a problem if I continue to do this, or do I really need one battery dedicated to the trolling motor? I thought you just couldnt hook the tm up to the cranking battery, which I dont have anyways because my gas engine is not an electric start model.

Hopefully all of those questions make sense, haha. I am pretty good when it comes to getting everything hooked up and run through the boat, I just want to make sure I am wiring in the right stuff before I make a really costly mistake. I certainly appreciate any help or suggestions yall might have.

Thanks and take care!

- Jonathan

[sneaker]

The 10 gua wire will easily handle 50 amps so you don't have a problem there. The change in guage will have no effect for this application. Keep the 10 gua wire short, under 6 ft, to reduce voltage drop across the lighter wire.

Trolling motors draw current in large chunks and are notorious electrical noise generators. This noise on the battery voltage will often interfere with fish finders and radio gear. So TM mfgrs recommend a dedicated battery for the motor. However you can but cheap (under 15 bucks) noise filters for the battery that you can insert in the fish finder power feed that will do an adequate job of cleaning up the battery noise. It should be rated for 12v at 1/2 or more amps.

I wouldn't use a fuse in the motor battery lead. If you blow it, a replacement may not be handy. You can find a type 1 circuit breaker(manual reset) at any auto store for less than 15 bucks. Type 2 C/Bs are auto reset and are not recommended because the TM mfgrs want you to clear the problem causing the breaker to blow, usually weeds on the prop or fishing line wrapped around the prop shaft. On a jon boat with 2 aboard the motor will draw 50 amps only briefly if you use full throttle accelerating from a stop. Once the boat gains a little speed the current will drop to 30-35 amps, less on a lightly loaded boat. Mine draws 28 amps at max speed.

[MA1232]

Hi Jonathan,

Sorry for hijacking your thread but I have a question for Sneaker if you don't mind.

Currently, I have a  type 29 battery and a 46lbs TM.  I just pickup a Fishmark 320 and planning on connecting it directly to the battery.  After reading your post, I'm hoping that I don't have to add a "noise filter".  However, If it is going to be a problem.  Where can I purchase one of this noise filter?  Can you post a link to a picture of a "Noise filter"?

Thanks

[H-SCbassman]

Hey MA1232,

No problem. I was actually wondering where you could find one of the noise filters as well because I want to try and hook the depth finder and TM to the same battery.

sneaker,

Thanks for all of the great information! That definitely helped me out a lot, and I can see what you are saying about the manual reset fuse and about the noise I would pick up from the TM on my sonar. Hopefully I can get this project finished up tomorrow so I can get back out on the water!

Thanks again!

Jonathan

[bowtech_182]

RF choke from Radio shack

http://www.radioshack.com/product/index.jsp?productId=2103222&cp=&sr=1&origkw=rf+choke&kw=rf+choke&parentPage=search

[MA1232]

Wow!  I never know that those thing were use to reduce electrical noise.  I have a lot of them from old CRT monitor cable.  

Hey Bassman,

LadyFlyFisher post a great idea over on this thread.  She used a 12v Makita battery for the fishfinder.

http://www.bassresource.com/bass_fishing_forums/YaBB.pl?num=1211988351

Tight Line!

[sneaker]

Noise filter- Any filter you buy should have 3 components in it, a capacitor followed by an inductor, then another cap. It is called a filter-isolator. Unfortunately no mfgr I have found published specifications for the filters ability to attenuate noise. So it is kind of a crap shoot. I have been using a filter made by Pyramid, model NS-10. Cost is 5-10 bucks and it is easy to install. Just type pyramid ns-10 into your browser and get one on-line. Keep an eye on their shipping/handling cost.   :-/

[H-SCbassman]

MA1232,

Good call on that link. I like that idea that LadyFlyFisher has about using the 12v mikita battery. I never thought about that, but that would certainly work. I am definitely going to look into doing that.

sneaker,

Thanks for the info on the filter. I think I might go ahead and get the same one that you have just to give it a shot. I definitely need to try something. I took the boat out today and could definitely see a difference in having my sonar and TM hooked to the same battery. Like you said, it picks up a bit more noise. I figure I will give the filter a try, though. If worst comes to worst, at least I'm only out by 5 or 10 dollars.

Thanks again yall!

[George Welcome]

Minn Kota power heads carry a ground wire to a circuit to reduce rf noise. If you use the same battery to start your big motor on your trolling motor you will instantly short out the circuit board which will feed 12 volts directly to the case of the motor. This creates instant electrolysis.

Do not use the same battery for both applications. It is not so simple as a noise filter.

If you want to bypass this setup so as to use one battery. Remove the cover and cut the green wire that you will find coming up the shaft.

I am only telling you how - I am not recommending that you do it.