Wiring

[High Hopes]

I am about to wire my engine w/ idiot lights. Comments are welcome. -Steve

[High Hopes]

No comments from anyone? I was hoping someone would find flaws. Guess I'll wait for the curls of smoke.

Later guys.

[Kelly]

Here is Don's A4 D.C. power scheme. Perhaps you can compare and come back with some specific questions?

I hope this helps.

Kelly

[High Hopes]

Hi Kelly,

I think the only thing I have done differently is the ammeter gauge. I want it to show house current draw.

But mostly, I was wondering what people thought about the Engine and Alternator warning lights. Is this a mistake? My wife, and other newbies will be at the helm. I wanted to simplify everything as much as possible, especially "attention-to-gauges" wise. This layout leaves only the fuel gauge, which everyone understands, and the tachometer of which I will instruct users, "Never go over 2000."

The warning lights are truck marker lights which are just a bit bigger than the 2" gauge holes. There's two of them, one yellow and one red.

[rigspelt]

Interesting. Nice thing to do ponder early in the morning with a cup of coffee. I'm starting to plan a major rewire on my third boat, so you've got me thinking. Got a 20-something sailboat. Warning: I am not a professional, just an amateur boater.

I see your point about keeping it simple at the helm. I'm thinking of keeping the engine panel in the cockpit simple too, and moving some gauges into the cabin at the entry hatch. The engine panel is hard to see at the wheel, and I could keep an eye on the gauges in the cabin when someone else is steering. I like the idea of audio buzz warning for engine temp and oil pressure. Moyer sells a nifty kit that's on my wish list. Presumably it can be wired to both buzz and power warning lights?

How does one rig an alternator warning light to show under and over charge? I guess the worry with the idiot lights would be not recognizing a burnt out bulb, but I presume they the idea is to wire them to come on during ignition, so the operator can check them.

Like you I want a voltmeter and ammeter for alternator output. Like you, I plan to add a tach and engine hour meter. I think the minimum at the helm would be blower, ignition switch, tach, temp buzzer/light, oil buzzer/light, and battery voltmeter or alternator warning light (to watch for alternator over/underchage under way). The rest could be below: fuel, ammeter(s), hour meter, engine temp, oil pressure. I want a battery battery-selectable voltmeter below in any case, so I can keep an eye on the condition of the batteries. The question is whether another voltmeter is a must in the ignition panel.

Ideally I might want ammeters for house and engine draw separately. I think I might prefer to use a shunt for amperage measurement and run direct cables to engine and house, but maybe I don't understand enough about simply running the output first to the type of ammeter used in these setups, and then running outputs to engine and house from there as in the orginal design. Seems to me that a shunt approach would take the ammeter gauge offline and remove a source of power supply failure? On the other hand, the single ammeter keeps things nice and simple, is cheaper, and shows house draw when the engine is off. So maybe that's good enough.

I'm pondering running the alternator output to a voltage sensitive relay device that charges the main battery preferentially, then both batteries automatically when the charge comes up on that battery, and a pair of output switches that allow me to separately control batteries for output. The BEP 716 battery distribution cluster looks ideal, but I don't think it likes a low output alternator (smaller than 55 amp - currently mine is 35 amp). I think the BEP VSR cluster chatters or something with that small an alternator. Still tryiing to figure all that out.

Should your brown engine instrument power wires branching from the fuel gauge be purple? And isn't there a spec that requires the purple power wires to run from device to device on the ignition panel, not branch form one point like that?

Where are the #8 red wires going from the battery (+) posts? Shore power charger?

[Don Moyer]

Steve,

I'm not sure how your alternator light works. It appears that you have it in series between the ignition circuit and the field exciting lead (which should have a diode to prevent current flowing from the alternator). This would have your ignition circuit supplying power to the light whenever the ignition switch is on.

Also, your ammeter would show the total current passing through it and over to the house panel, even without the green lead you show heading toward the house panel (with the arrow head on it).

Don

[High Hopes]

Helllo Don,

This is the signal from the MMI 55 amp alternator marked Indicator Light Sensor. I am not sure of the wiring, but I think that the bulb in series will limit current to the field coil. I am thinking that when the battery is low, the ignition switch will be at a lower volatge than the alternator when it is running and therefore light the bulb - indicating a problem with the battery.

Please let me know if you think this is way off base. A simple schematic is attached. I was better at reading these years ago.

On the ammeter, it is intended to be a battery ammeter which will read positive when being charged, and negative when being used. It also sums the current for house use (negative) and alt charge (pos) when both the house circuits and the alternator are in use. Zero amps is the middle of the scale on the ammeter I have.

Steve

[High Hopes]

rigspelt,

Taking your comments one at a time...

Interesting. Nice thing to do ponder early in the morning with a cup of coffee. I'm starting to plan a major rewire on my third boat, so you've got me thinking. Got a 20-something sailboat. Warning: I am not a professional, just an amateur boater.

I see your point about keeping it simple at the helm. I'm thinking of keeping the engine panel in the cockpit simple too, and moving some gauges into the cabin at the entry hatch. The engine panel is hard to see at the wheel, and I could keep an eye on the gauges in the cabin when someone else is steering. I like the idea of audio buzz warning for engine temp and oil pressure. Moyer sells a nifty kit that's on my wish list. Presumably it can be wired to both buzz and power warning lights?

>>> I have to get on my knees to read my current cockpit gauges.
>>> I do have Don's kit and it is providing the sensors for the ENGINE light. I think his new kit might even have a light as well?

How does one rig an alternator warning light to show under and over charge? I guess the worry with the idiot lights would be not recognizing a burnt out bulb, but I presume they the idea is to wire them to come on during ignition, so the operator can check them.

>>> The ALT light will not show over charge. A voltmeter might best serve that purpose.
>>> The ENGINE light will come on when the ignition is first turned on and there is no oil pressure. So both bulbs should light when the key is first turned, and the engine isn't started.

Like you I want a voltmeter and ammeter for alternator output. Like you, I plan to add a tach and engine hour meter. I think the minimum at the helm would be blower, ignition switch, tach, temp buzzer/light, oil buzzer/light, and battery voltmeter or alternator warning light (to watch for alternator over/underchage under way).

>>> The ENGINE light serves for oil and over temp, both. I am locating the electric meters next to the battery switch below deck so I can monitor either battery.

The rest could be below: fuel, ammeter(s), hour meter, engine temp, oil pressure. I want a battery battery-selectable voltmeter below in any case, so I can keep an eye on the condition of the batteries. The question is whether another voltmeter is a must in the ignition panel.

>>> A single gauge AFTER the battery switch will show the voltage of the selected battery, or both together, should you want to measure that.

Ideally I might want ammeters for house and engine draw separately. I think I might prefer to use a shunt for amperage measurement and run direct cables to engine and house, but maybe I don't understand enough about simply running the output first to the type of ammeter used in these setups, and then running outputs to engine and house from there as in the orginal design. Seems to me that a shunt approach would take the ammeter gauge offline and remove a source of power supply failure? On the other hand, the single ammeter keeps things nice and simple, is cheaper, and shows house draw when the engine is off. So maybe that's good enough.

>>> Putting the ammeter after the battrey switch makes it selectable. Use a meter that reads negative as well as positive, and you should see the house draw.
>>> To measure both battery currents, just wire two meters, one for each battery. I would hard wire this. I started with a complicated wiring circuit which did most anything, but it was too complicated to understand instinctively. An extra meter is cheaper anyway.
>>> But you raise an interesting point. In my design, there isn't a way to use a house battery without it being connected to the alternator. Do you want to charge the starter battery while using the house battery? Hmmm. Sounds like an additional battery switch?

I'm pondering running the alternator output to a voltage sensitive relay device that charges the main battery preferentially, then both batteries automatically when the charge comes up on that battery, and a pair of output switches that allow me to separately control batteries for output. The BEP 716 battery distribution cluster looks ideal, but I don't think it likes a low output alternator (smaller than 55 amp - currently mine is 35 amp). I think the BEP VSR cluster chatters or something with that small an alternator. Still tryiing to figure all that out.

>>> This approach is essentially an alternator switch. I'm not sure I want to get that complicated. I have thought of adding a second regulator to the alternator - but ths is somewhat complex. A simpler approach is to use a negative battery isolator and connect it to the alternator. There is a snag with this approach, too. There is a voltrage drop across battery isolators. The regulator output would need to be adjusted up a volt or so. There are now solid state switches that show almost no voltage drop, but this gets into electronics and I want to keep things electical."

Should your brown engine instrument power wires branching from the fuel gauge be purple? And isn't there a spec that requires the purple power wires to run from device to device on the ignition panel, not branch form one point like that?
>>> I have ignored ABYC color codes. I will probably buy a spool of yellow or orange wire for the whole thing. I like the color yellow.

Where are the #8 red wires going from the battery (+) posts? Shore power charger?

>>> These are for bilge pumps which are controlled independently of all other curcuits. One pump for each battery. They are not interconnected even between themselves for redundancy sake.

[High Hopes]

I just noticed that the engine off when the battery switch is turned off. This prevents the alternator from running without a load and allows the engine to be turned off from the battery switch. But I wonder if the latter is a good idea.

Any thoughts or experience with this arrangement?

[msauntry]

Something to keep in mind...
I just rewired my engine and found common buses useful. I used one off the IGN to power the gauges and another off this to the engine compartment for all the IGN powered things in there (oil pres. switch, coil, hour meter, etc.)

I noticed my IGN and my COIL positive were getting stacked pretty high with leads and this solved the problem and made for a cleaner installation.

[High Hopes]

msauntry,

I am planning to daisy chain the +B from terminal to terminal. Here is a slightly updated schematic which shows that a little better. With the daisy chaining, there is a sort of bus with no more that 2 connections per terminal (except for the gauge lamps). Note the brown wires. Also, the common B+ on the engfine will be three wires on the oil pressure safety switch. That way I can remove the coil wire and turn on power without burning out the igniter.

ms auntry?

Steve

[msauntry]

Looks good to me. Good luck!

[High Hopes]

Thanks, MS.

Here is an update after reviewing the ABYC specs.

[keithems]

what does "spst" stand for?

[toddster]

Refers to the type of switch: single-pole single-throw

[Sony2000]

I have a small question of wiring. I'm running without an alternator. Where can I attach the alternator wire, to give me a negative indication on the ammeter?

[edwardc]

Originally Posted by Sony2000

I have a small question of wiring. I'm running without an alternator. Where can I attach the alternator wire, to give me a negative indication on the ammeter?

If the ammeter is in series with the battery, as shown on the diagram in post #13 of this thread, it will read both + (charging) and - (discharging). When the alternator is disconnected, it will still read the - (discharging) current.

If the ammeter is wired in series with the alternator, as shown in post #3, it can only show the + (charging) current. With the alternator disconnected it will show nothing.

So, based on your question, I'm assuming your ammeter is wired in series with the alternator. To do what you want, you should move it in series with the common terminal on the battery switch and the main 12v bus. This way all current to and from the battery (with the exception of the starter current) will be shown by the meter.

[Cool Beans]

Not to keen on #4 primary and starter wires, but please at least fuse them at the batteries. Also, I would say to dump the ammeter all together and jump a #4 wire from the alt. output to the starter lug. Your charging circuit is much simplified then and if you fuse at the battery that entire section of heavy amp circuit is protected. Also more alt. charge goes into the battery (being less wire to run through, less voltage drop).

Rely on your voltmeter for information about your alternator. Once energized, the voltage from the alt. should be 13+ (which signifies it is working), and as loads are applied the voltage will drop (which signifies power drawn). If your alt. craps out, the voltage won't increase with the engine running and you will know it is bad.

If you really want to monitor your power consumption, invest in a battery monitor. It would also replace your volt meter.

One final suggestion would be to look into getting away from the start/house battery designation and go with a Primary/Secondary battery setup.

The Primary Bank is connected to #1 and provides starting power, house loads, and takes all charging. #2 on the switch connects to the Secondary bank and is for emergencies only. You just switch to this battery every week or so to top off the charge and make sure it is functional in case something happens and you need to depend on it. You could provide some secondary trickle charging to it. . .

I'm setting up my boat like this and now seeing it, makes a lot more sense to me. It also makes the wiring easier since I'm not trying to wire both banks together for certain dynamic uses and I don't need to constantly remember to flip the switch back and forth.

Just my free 2 cents

[hanleyclifford]

Since I never know which battery is going to go south on me I have all batteries wired to the main buss bar but switched individually. I use the alternator to feed the main buss bar and whatever batteries are switched on will receive whatever charge they require. All my batteries are deep cycle flooded group 31 s so it makes no difference who does the starting and who does the house. Flexibility is complete and I like to rotate duties so each battery gets routine scrutiny. FWIW

[positron]

I had my boat surveyed last spring and the only major thing the surveyor insisted on for the electric system was a fuse at each battery positive terminal, to protect the heavy wires running to the main battery switch and the starter motor. This was not a requirement when most of our boats were built. I went with a fuse/holder combination that attaches directly to the battery post. Like most other safety items it seems like a big waste of money until you need(ed) it.