Ok,
I've got it working. I haven't finalized the installation, but I know what I've done works.
To start, I had found the same diagram that VEEK had posted, and planned on adapting it to the SPF after reviewing the SPF schematics.
If you look, you’ll see that the blue “warning light” wire and the black “ignition” wire are both part of the same circuit, and come on with the turn of the ignition key. I tried using one, the other, and then both as the “exciter”, but settled on just using the blue wire. It gives me power to the regulator when I need it (on with the key), and when the car is in the run position with the engine not running (or when the alternator not working), the warning light glows. The light turns off when the engine starts (if the alternator is functioning). That’s what I wanted.
The downside is two-fold. First, if the dash light burns out, your alternator will not produce power. Second, from what I’ve read, you could potentially run your battery down or kill your regulator if you left the key in the run position for a long time without the engine running. An alternative is to use the black “ignition” wire. This bypasses the dash light, but doesn’t eliminate the other potential problems. VEEK’s diagram suggests using a diode to eliminate these last two problems, and if wired correctly, could be used on either circuit.
The actual install is easy. Just follow the diagram.
1. Spice blue “warning light” wire to wire coming from “I”.
2. Put a female spade terminal on the wire coming from “S”, and slide it on the male spade on the side of the alternator.
3. Put a ring terminal on the wire coming from “A”, and double it up on the lug to which the large battery cable attaches to the alternator.
Note the suggestions re adding a mega fuse, and eliminating the ammeter. I’ve ordered a voltmeter, but they are stuck in customs for now. Something about importing parts that look like bomb-making materials.
I have part numbers for those who want them, but really you’ll just need to match the wire harness to the regulator on your alternator. Cost me $30 for the harness. You could do it on the cheap with spade terminals, but why do that on a 6 figure car?
If anyone has any suggestions, I’d love to hear them. If my car burns to the ground because of this, I’ll be sure to warn you.