Wiring Diagram Critique

[DerDer]

I am restoring a 1973 Starcraft 16' SuperSport. I ripped out all the old wiring and now going to re-wire. I am hoping someone with more knowledge can take a look and let me know if everything is ok.

I included two battery switches. Somewhere I heard it's best to do this on an aluminum hull boat to isolate the battery in case of a short to the hull. Is this true?

I will be using an above sole plastic gas take underneath the splash well. Is it ok to have the battery, batt switches and neg bus bar under the splash well also? The area won't be closed of but will have marine vinyl hanging down to cover the area.

Thanks for your help,
Matt

 

[ajgraz]

Re: Wiring Diagram Critique

Is the battery switch a simple "master switch?" Good idea to have that on the positive side, especially on an aluminum (to prevent shorts, as you say). I believe it's an ABYC standard anyway. Having the big fuse in that line will be double protection.

I don't see the need for a master switch on the negative side of the battery. What is that supposed to do? EDIT: Maybe that helps stop galvanic corrosion on a tinny that stays in salt water?

Don't see any reason not to have battery and bus bar under the splashwell, hidden by a curtain. My boat is rigged that way. On the aluminum boat though, be sure that busbar in the rear is electrically isolated from the hull. And have the battery in a covered box, or at least put a rubber boot over the positive terminal(s).

Do you keep this boat in the water? Or do overnight sleeps? Do you really need an automatic setting and float switch for the bilge, or do you just need a simple on-off?

Otherwise the diagram looks alright to me. What are the lengths of these runs, amp draws, wire gages, and fuse sizes?

 

[Silvertip]

Re: Wiring Diagram Critique

Once again, I have news for the "grounding to the aluminum hull" experts. The instant you bolt an engine to an aluminum hull you already have a ground path between the hull and the battery. It has been discussed here in great detail. Geez -- follow the negative battery cable from the battery to the engine. It bolts to the engine block does it not?? How is the engine fastened to the boat? With steel bolts is it not? Do you think for an instant that a couple mils of paint is going to prevent an electrical connection between the metal engine mounting bracket and the hull? If you don't believe this to be true, break out your trusty ohm meter and see if there is continuity between the hull and the engine block. So what's the big deal. A short to the hull is no different than a short to ground. The fuse blows and there you have it. You are wasting money on the switch. It is simply not necessary. I would also eliminate the negative buss bar at the stern which eliminates about five points of failure. Crimp those ground leads into a single ring terminal and connect it directly to the battery. If you attach the bus bar to the aluminum hull haven't you created a hull-ground which is such a no-no?

 

[ajgraz]

Re: Wiring Diagram Critique

Wow, Silvertip! Did someone p*ss in your Cheerios this morning? I'm sure you are very knowledgeable, but your communication skills could use some work.

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Yes the engine grounds through the hull. But that's no reason not to use an isolated busbar. At least you can try to keep the galvanic corrosion isolated to the transom. Also, while moving the battery (to fill water, etc.), I believe failure is less likely--at the least, easier to diagnose and repair--if you have a single ring terminal or lug to the battery (i.e., ground strap to the busbar) than if you have multiple ring terminals or multiple wires into one ring terminal at the battery.

It is easy to isolate the busbar from the hull; either use something like a Blue Seas Systems minibus with a phenolic baseplate, or screw any old busbar to a piece of plastic and bolt the plastic to the hull.

And as for the master switch, that is ABYC standard, aluminum hull or no. I misspoke when I said "prevent shorts"; I meant to say it would act to help prevent battery drain from a "trickle" short.

 

[Silvertip]

Re: Wiring Diagram Critique

If it is a standard, why aren't small recreational boats that do not have shore power capability wired that way? I didn't say it wouldn't work did I? I "suggested" that it was unnecessary. I also "suggested" that the bar creates multiple points of failure. Not that it wouldn't work. As for whizzing in my Cheerios, I eat healthier than that. Had they whizzed on my fruit & veggies, THEN I would be upset. You are participating in an on-line forum -- pull up your big boy panties. It is your option to take or ignore advice and comment. As for communications skills -- if you only knew!!!!! Just trying to head off another ground-to-the-hull discussion.

 

[bruceb58]

Re: Wiring Diagram Critique

Grounding to the hull is fine as long as you aren't expecting any current to be flowing through the hull. The only purpose of grounding to the hull is to get it at the same potential as the other grounds on your boat.

 

[DerDer]

Re: Wiring Diagram Critique

I'll drop the 2nd battery switch.

Thanks for the help. I appreaciate the knowledge on this board. I've learned a lot from you guys.