A4 Electrical Wiring Schematic

[jkenan]

I just purchased a 1977 Ericson 29 and am doing several upgrades to the engine. The biggest problem I have encountered is that the wiring connected to the engine is a cable monster... non-terminated loose wires, add-on relays, lots of old, stiff electrical tape no longer doing its intended job but still hanging on... you get the picture. I WILL remove all of it. The problem, of course, is what I need to do at that point. Any diagrams, literature, etc. would be much appreciated. I purchased the A4 maintenance and overhaul manual, but it does not diagram essential electrical connections.

I'm neither a mechanic nor an electrician, but can do this with the right information. Any thoughts?

Thanks in advance.

John

[Don Moyer]

John,

For some reason, this past year has seen a large number of our customers facing exactly your same problem. We have developed a kit over the past several months containing all the correct ABYC-sized and color-coded wires, terminals ends and detailed guidance for replacing the DC power distribution on an Atomic 4.

I'll attach the schematic which we include in the kit to give you an idea of what's involved. Our instructions recommend removing all of the existing wires, and to then keep everything having to do with house equipment out of the engine electrical system.

The kit should be posted in our online catalog by Tuesday or Wednesday of this week.

Best regards,

Don Moyer

[Baltimore Sailor]

Looking at this wonderful drawing (thanks for posting it!), I notice that the ammeter connection only shows it sitting across the orange wire from "batt" on the ignition switch to the "output" terminal of the alternator. Isn't there also another connection from the red battery terminal on the starter solenoid to the ammeter? Or, is that something that varies between ammeters?

[Administrator]

It may help you to think of the current flow as coming FROM the alternator. Using the alternator as the starting point, the current flows through the orange wire, through the ammeter, then to the "Batt" position of the ignition switch and back to the starter solenoid through the red wire you mentioned.

Don

[Baltimore Sailor]

OK, thanks. That makes it more clear.

[castinemarine]

I have been looking for the wire to rewire the Ignition switch to the starter solenoid. Does anyone out there know where I can procure about 18' of this discontinued product? It's 12 AWG Tinned Copper primary wire, Yellow with a Red Stripe. Someone must have a bit of it around. Thank you all for looking or putting me in touch with a source!

Chris

[tenders]

I would suggest buying yellow wire and drawing the stripe on with a Sharpie, or finding some red electrical tape and putting a few turns of it around the yellow wire every six inches or so.

[67c&ccorv]

What kind of fitting do you use on the end of that 8 AWG wire that connects to the ignition switch?

I am using a brand new Cole-Hersee ignition on/off switch with a new starter button to turn the motor over. The connections use #8 screws - even the smallest terminal fitting that will go over an 8 AWG wire will probably slip right over the #8 screw fitting on the starter switch.:(

Any thoughts?

[rigspelt]

What kind of fitting do you use on the end of that 8 AWG wire that connects to the ignition switch? I am using a brand new Cole-Hersee ignition on/off switch with a new starter button to turn the motor over. The connections use #8 screws - even the smallest terminal fitting that will go over an 8 AWG wire will probably slip right over the #8 screw fitting on the starter switch.:( Any thoughts?
I did a google search on "AWG 8 ring terminal #8" and found this http://www.doityourself.com/invt/u514925, but that's just an example. There should be a variety of options. Look for a good quality copper ring terminal, ideally with a built-in heat shrink/adhesive sleeve to make a nice "marine" terminal after making a proper crimp. See http://www.pbase.com/mainecruising/wire_termination.

[Drakkar]

Hello

In reference to your comment:

and to then keep everything having to do with house equipment out of the engine electrical system.[/B]

Where do you suggest that the house system (fuse panel, etc) hook up in your pdf diagram?

Where would you install a battery isolator ...i'm thinking the orange wire (alternator output) after the amp meter or in essence on the 8 gage red wire from the BATT post on the ignition switch... I have a 1/all/2 switch presently connecting both batteries.

p.s. do you recommend a relay isolator or a diode based one?

Phil:

For some reason, this past year has seen a large number of our customers facing exactly your same problem. We have developed a kit over the past several months containing all the correct ABYC-sized and color-coded wires, terminals ends and detailed guidance for replacing the DC power distribution on an Atomic 4.

I'll attach the schematic which we include in the kit to give you an idea of what's involved. Our instructions recommend removing all of the existing wires, and to then keep everything having to do with house equipment out of the engine electrical system.

The kit should be posted in our online catalog by Tuesday or Wednesday of this week.

Best regards,

Don Moyer[/QUOTE]

[rpowers]

I am considering installing an amp meter between the alternator and battery.

What should it be reading with the engine running? Engine off?

If there is a +60 side to the dial, why is there a -60 side also?

Thanks!

[rigspelt]

I am considering installing an amp meter between the alternator and battery. What should it be reading with the engine running? Engine off? If there is a +60 side to the dial, why is there a -60 side also?
Thanks!
I'll take a crack at this from my limited experience. The (+) and (-) of an ammeter refer essentially to the direction of current flow, which can be one way if the circuits are draining power, and another if the system is being charged. One has to know one's own system. Zero just means either the two flows are balanced, or no current is flowing. So the answer depends on where the shunt is positioned in the circuits, and what appliances are drawing or charging. The Amount of amps depends on the state of battery charge too. After startup, a start battery will draw more amps initially (maybe 10-14 depending on the nature of the system and age of the batteries), then the current will gradually decrease until the battery is recharged, and finally hover at a lower amperage depending on what draws there are on the circuit. Actual amperage also depends on the type of regulator on the alternator.

I went with a voltmeter in the ignition circuit to tell me the state of the engine start battery and whether the alternator was charging or not, and put an ammeter in the house battery circuit to monitor the house draws. There are lots of ways to do it.

[rpowers]

Thanks for the answer about the amp meter. Makes good sense.

Next Question:

Why does the alternator charging current go through the ignition switch, to the solenoid, then finally back to the battery?

What would happen if the alternator out current was wired directly to the battery (or 2 batteries)?

Thanks!

[sastanley]

rick, I think if you did that, and put the ammeter shunt (I assume you will use a shunt style) then you can only see current thru the alt to the battery...i think...meaning, it is a one-way gauge. I personally have never used a shunt style....in my '78 Civic, I had an ammeter and had to run a cable from the battery to the gauge and back before it went to anything else. What a pain!

If you want to measure in & out current of the battery, you need to wire the boat so that wherever your ammeter is located ALL current passes in both directions thru that cable. It isn't complicated, but can require long runs of thick gauge wire.

I chose to eliminate my ammeter (in the gauge pod in the cockpit) and have a short run from the alternator plate directly to the battery. I like rigs' idea....if you see ~14 on a volt meter when the engine is running, you know the alt. is working. Amps are cool, but it is a lot of extra work to see it!

[rigspelt]

Why does the alternator charging current go through the ignition switch, to the solenoid, then finally back to the battery? What would happen if the alternator out current was wired directly to the battery (or 2 batteries)?
Sounds like you have the older style of wiring, which works but requires long runs of alternator output cabling. When I rewired the boat, I chose instead to run a short properly sized red cable from the alternator's "output" post to the big battery cable post on the starter solenoid, where a big red cable is attached that runs directly to the positive post on the engine start battery. That allowed me to replace the ammeter in the ignition panel with a voltmeter, to simplify the ignition system wiring, and to separate the house from engine circuits. In the old way on C&C's, power for house circuits came from the ignition panel, because that's where the alternator output ended up, so there were much longer wire runs than I have now for the house circuits, and house and engine circuits were not separated.

There are some interesting threads on this forum on wiring - try searching on "schematic". Examples:
http://www.moyermarine.com/forums/showthread.php?t=2727
http://www.moyermarine.com/forums/showthread.php?t=2685
http://www.moyermarine.com/forums/showthread.php?t=1341
http://www.moyermarine.com/forums/showthread.php?t=2580

[SimonP]

castinemarine was looking for some wire - yellow with red. A more permanent DIY approach than vinyl tape is to get some heat-shrink (polyolefin) tubing, commonly used in hobby electronics. This stuff is great for insulating solder joins etc, and comes in a range of colors and sizes. often, I use a short length (1/4") at each end of a custom wire to color code it. You can use a heatgun to shrink it, but I usually just wipe to with the shank of my soldering iron. It closes up so tight I'd guess it's as good as airtight.

[Maurice]

Don,

Great Post #2 wiring schematic. I have a complete identical gauge cluster from a newer boat than mine. My friend re-powered his '"79 C&C 34 with diesel and I bought the engine and instrument cluster about 2 years ago.

The wires attached to the gauges are all long, coiled, and a brief glance tells me they are the same as on my "76 C&C 30. I was figuring I'd replace the weathered cluster on my boat this spring.

Your diagram will make that job a walk in the park.