Alternator wiring , Help please!

[mphatc]

I am replacing the ancient charging system on the Corsican . . eliminating the separate voltage regulator, and installing a new 70 amp alternator manufactured by ARCO Marine.

The terminals on the back of this are labeled:

Bat . .Battery
P , a single spade . . ????
S ????
I ????

There is a separate ground lug . . .

The S & I are part of a small two pin connector .. .

I chose this unit as it easily retro fits in the place of the old unit . . .

TIA,
Mario

[BlownCrewCab]

There is an even easier "one wire" alt available. are you stuck with the one you have (alternator :))

[mphatc]

As I'm impatient and want to go boating this weekend, I took the alternator to a friend who is a rebuilder of all things electrical for cars . . here's the information . . .

In the hope that this helps others with the old H&M charging systems

This alternator is a very easy replacement bolt on as it has the same configuration and arrangement of fasteners.

part number Arco 20820
70 AMP

The terminals are:

P: tachometer drive, ignore this for this application
I: ignition , feed from an ignition hot, I'll piggy back this off my electric choke power feed.
S: Voltage sensing, tied directly to "Bat" terminal

Ground is unlabeled and a separate post off the body of the alternator

Mario L.

[BigGrizzly]

Do not go to the choke power feed, go directionally to the ignition switch, unless the wire your is coming directly from the ignition switch before the switch with no resistor.

[mphatc]

Randy,

Excellent point, . . my wiring is direct from the switch and I had considered this . .

It's all in and works great , no need to even change belts . .

Mario L.