one-wire alternator wiring help

[jt1989]

Hello,
I just purchased an ac delco one wire marine alternator and I am wondering how to wire it...I put a new motor in the boat and all new wiring so I dont have the old 3 wire alternator wiring, which is why I purchased a one-wire alternator...I am using 6 gauge wire from the alternator to battery...but is that it? Does the alternator ground through the mounting post? Any help would be great! Thanks
Here is a link to the alternator I bought...
http://www.dbelectrical.com/p-3609-n...e-adr0334.aspx
Thanks

[Maclin]

What year, manufacturer and engine size are we looking at?

Those other two wires may be integral to the correct operation of your particular engine system. For example some installs use the alternator wiring as the source for electric fuel pump power, when the engine stops so does the fuel pump power.

Wiring to the battery will be correct for bascis installs, but let's take a look at exactly what you are working with.

[jt1989]

The motor I put in is a chevy 383 stroker. I already have the electric fuel pump wired in...without the alternator, right now everything is working fine...including all the gauges, stereo, etc. I have 2 optima red top batteries wired in parallel for my bank...also...is there any way to wire this one wire alternator to where I can get an ammeter reading that will show a kick up in voltage when the alternator is internally "kicked on".

[Maclin]

An ammeter has to be wired in series, alternator wire on one terminal, then the other terminal to the battery. Ammeters are pretty stout because they have to take the whole amp load for the whole circuit.

Regarding the rest of it, like the fuel pump and all, is all that still OEM meaning fuel pump gets power only while cranking or when the engine is running (via oil pressure switch) ?

It would be best to give us the manufacturer, like Merc or Volvo or OMC to be able to help more and keep this safe.

[jt1989]

The motor is completely custom built...the boat came with a 350...that was completely shot...so...I built a "marinized motor" from a 350 block and used the bolt on parts from the old 350 such as exhaust manifolds...and I guess thats really it...everything else is new lol...I have an msd ignition box that the tachometer reads from...the fuel pump is wired to ignition switch, with a fuel regulator and fuel pressure gauge between fuel pump and carb. The stereo, bilge pump, bilge blower, lights, etc are wired to a fuse panel that is wired directly to the batteries...so I dont need the key in the run position to run these accessories...So I would have to run 6 gauge wire from the alternator, to the ammeter, back to the battery? Correct.

[Don S]

What outdrive do you have, what year is the boat and who's instrument panel? Mercruiser, Volvo, OMC, as Maclin stated, we have to know that information in order to tell you how to wire things. Ammeters are a thing of the past, but wiring has to change in the harness to make things work.

[Maclin]

Ammeters are a fail point, if they burn out you have no power. You also have to run very large gauge wire a long ways on a boat if you want it up on the dash with the rest of the instruments, not worth it in my opinion.

I also feel you are on a not so safe path already regarding the fuel pump and other stuff, don't get in a hurry. Marine component stuff is wired to meet regs and also to be safe. I recommend to not skip or bypass safety items that were already there. If you switched from mechanical fuel pump to electric then to be safe you cannot just wire to the battery or ignition. There needs to be a method to make sure the fuel pump cuts off with the engine. Merc, OMC and Volvo all do it differently, which is why we have asked what you have 3 times now...

[Silvertip]

A properly wired electric fuel pump will generally be wired through the oil pressure switch. This kills the fuel pump should the engine die and heaven forbid, there is a serious fuel leak and fire. A fuel pump that stays running even if the engine is dead means the pump is fueling the fire. That same safety circuit then needs a bypass to allow the pump to run until the engine builds oil pressure.