***Boat wiring questions from a complete greenhorn, need help!!!***

[WalleyeGuy11]

Hi all, I am new to the forum but have been reading lots of threads on here and they have been extremely helpful.

I am in need of some help, I am in the process of rebuilding an '88 starcraft, and have lots of questions. I think it would be a good idea to list what I'm running and what I would like to add to the boat.

The boat has a 40hp Johnson (year unknown) and it already has a bilge pump, a livewell pump, and a fuel pump, with normal courtesy lights. It is also wired for a fish finder.

What I would like to do is run a newer Minn Kota trolling motor, add a stereo with 2 to 4 speakers (whichever would be easier to wire) and also add some LED light strips for interior lighting.

My first question is, is it possible to run all of that off of 2 deep cycle batteries located in the rear of the boat? --- I read somewhere that you can hook the two batteries up in paralell?---

Second, I sure could use some guidance in wiring in all of the add-ons listed above, running wire doesn't scare me, what does, is hooking things up incorrectly and messing up the whole project.

Thirdly, the stereo, I've never added a stereo to something that hasn't had one before, how difficult of a task is it to wire one in?

Would everything be ok to be ran off of only 2 batteries? Or would I need a third one?

Lastly, is there any way I could hook up a charging system, to where I would only have to plug in one cord and charge all the batteries at once? Possibly some sort of an on board charging system?

I'm in dire need of assistance and from what I have read on this forum there is a few real guru's on here, I look forward to your replies, and I thank you so much in advance!!

 

[alldodge]

Everything except the trolling motor, can be done off one extra battery, but depends on if the stereo also has an amplifier, and if this will be more then a one day outing.

Normal stereo, led lights and other such doesn't draw that much. Now the trolling motor does and depends on how much it will be used. Assuming your installing a 12V trolling motor and not a 24V model would suggest two group 27 deep cycles and one starting battery (3 total). The trolling bats can be mounted in the rear, but this will require larger wire sizes to feed the trolling motor.

Using 2 or 4 speakers is easy enough but requires more speakers and wire

You can get a 2 bank battery charger to both charge the start bat and the two deep cycles.

 

[Silvertip]

You mentioned the engine is a 40 HP Johnson and that you need to wire a fuel pump. If that engine is being fed by an electric fuel pump you will be sitting in a "bomb" unless it has some sort of automatic disconnect should the engine stop without turning off the key. As for wiring things, head to your local library and check out a book detailing low voltage wiring. There are numerous wiring diagrams in this forum for basic electrical systems. For addition of a stereo you follow the directions with the equipment. As for the number of speakers, if you can wire just one, you repeat the process for the number of speakers you have. Every thing you add has a positive wire and a negative wire. Items that need a separate switch should be wired to a switch panel or combination switch/fuse/circuit breaker panel. Using proper wire sizes is also essential. Read - read - read:

 

[WalleyeGuy11]

Thank you guys for the responses.

AllDodge, so basically what you are saying is I will need to run 3 batteries total? I will have to look at the trolling motor, but I'm almost certain it is not a 24v motor. If the case is 3 batteries (2 in the rear running the motor, lights, accessories ect. And 1 in the front running just the trolling motor?) Does the 3rd battery in the front need to be connected to the 2 in the rear? Or is that an independent circuit? Thank you again.

Silvertip, when I peeled out the floor to uncover the gas tank, there was 2 wires coming from what I'm assuming was the fuel pump. There was a black port-hole cover in the floor itself that allowed access to this. I am not certain if it has an automatic disconnect or not. Where would this be located? I will hit the books and give it the ol college try in an attempt to educate myself on wiring. I am about as handy as an amish blacksmith when it comes to electronics. But they are definitely a necessity. Thanks again

 

[alldodge]

No, your trolling motor will need 2 bats, and would need this if it was 12 or 24V. If the bats are placed forward then you don't need as much heavy gauge wire to get to the trolling motor. Putting it in the rear just needs more wire.

Being an OB you don't want them connected together, but can connect the grounds together which would be good. The battery charger will be connected depending or a 12 or 24v motor you choose

The wiress on the tank should be for the fuel sender

 

[Lightwin 3]

I think you're looking at the fuel tank sending unit (guage) feed.

Find out first whether or not your troll motor is 12 or 24 V.

 

[poconojoe]

I would like to emphasize that two batteries for the trolling motor need to be deep cycle and the battery to start the gas motor needs to be a starting type.

 

[poconojoe]

And as far as wiring, it's very important that you use the correct wire size for each device you connect. And each positive wire has to be fused according to the size of each wire. This is very important! If the wire is too small for the load of a particular device and it's not fused correctly, it may result in a fire. When you are on a boat, there's nowhere to run from a fire.

 

[Silvertip]

What you are probably looking at is a bilge pump that pumps water out of the boat. Two stroke outboard do not have any way to shut off an electric fuel pump if the engine dies like your car does (oil pressure switch). Some folks seem to think an electric fuel pump is better than the standard pulse operated pump used on two stroke outboards. Doing this means if the engine dies, the fuel pump keeps running and can fill the engine with fuel. You attempt to restart the motor and "ka-boom". So the long and short of this fuel pump thing is don't do it. It would help to know how big this '88 Starcraft is and whether or not you actually own the trolling motor or are going to buy one. If your boat is 17 ft or under you probably don't need a 24 volt motor. The biggest 12 volt provides 55# of thrust which is fine for nearly all except near-gale conditions. You only need one battery for that. As for the stereo, unless go nuts and add a gazillion watt amp you can run that off the starting battery. That leaves you with two batteries and two output on-board charger of about 6 amps per output. If you spend many hours at a time on the water, then perhaps a dual battery setup for the 12 volt motor is advised. Develop a well thought out plan for the entire project. I guarantee that if you just start stringing wire you will end up with a rats nest and poorly done job.