I think I want to wire the system this way...
Voltage Regulator
I- Disconnected
S- 12v run
A-12v constant
F- Field
Alternator ground to voltage regulator case
Yep. Not quite in that order, but the connections are correct for those letters.
You say stock. Is this a 45 to 60 amp alternator?
4 quick questions..
1. Do i need fusible link on the wire from the bat terminal to the battery?
Here's the long, multi-level answer. Hope it doesn't put you to sleep!
First, it sounds like your existing wire (is it Yellow by any chance?) goes into the harness, then through the ammeter, then back out to the starter relay's battery side. Correct? Is that wire Red?
If so, then yes, you should either have a fusible link there (like on a stock Bronco) or a Maxi-Fuse, in the 60 amp range.
If instead, you have a wire directly from the alternator to the battery (like you're talking about doing), then nope, you don't "have" to have one.
But it's a good idea.
I would say that, up until recently, most of the members here that have upgraded to higher powered alternators, have wired it directly with no protection.
Ford though, uses either a fusible link, or a Mega-Fuse with holder to do the job. Not sure if that was a running change, or just varied by vehicle, but they've done both over the years.
I like the Mega-Fuse idea though. More expensive up front, but easier to make a fix on the side of the road or trail. With a fusible link, you pretty much have to have all your favorite wiring implements to replace one.
Granted, if you blow a fuse or melt a link, you may have other issues not easily resolved, but at least the fuses are easier to test, and easier to replace.
Maybe it's just easier to buy protection nowadays than it was before? Pre-made harnesses are available from us, RJM, Painless, and probably the other vendors, as well as the junkyard.
Plus you can make your own with semi-easily sourced parts.
Lots of choices.
2. Should that wire go to the battery side of the solenoid or directly to the battery?
Either one is fine. The consensus is that, directly to the battery is the best, as any funky-monkey surges or anything like that is better absorbed by the battery, before it gets to the system.
That said, the most convenient spot is usually the starter relay, and even Ford (as well as all the other O.E.'s too, most likely) run them directly to their under-hood fuse boxes, or other terminal block. So if they think they can do it safely, I'm sure you can too.
Do you feel you really need to do this though? If your alternator is under 70 amps, you can just leave the existing wire that utilizes the ammeter.
Once you hook one directly to the battery though, that becomes the path of least resistance and the ammeter will only function occasionally.
3. Ammeter appears to work now but do I need to put the bat wire in that loop to get an accurate read off of the induction?
Yes, but you don't want to go to all that trouble. Sounds like you've got one already, and another one that's not part of the harness is just more potential trouble from rubbing on things, and just basically getting in the way.
Not worth the trouble unless you're totally into it and need the new wire for some reason.
I'm contemplating it with mine, but I'm just wired weird that way.
4. Alternator has a terminal labeled GRD (I assume ground) and another unmarked terminal very close to it. The sheet that came with the alternator showed using the unmarked terminal as ground. Which one do I use?
Correct. Both grounds. I've run into this before too. Some units label all the ground capable posts, others just label one. You can easily verify this with an ohm-meter to the case though. If they're connected, it's a ground.
Paul
