From the wiring diagram that I could find, wire from terminal L runs to lamp on instrument cluster, S and B run to B+ via 5A (ALT-S) and 100A (ALT) fuses respectively. The terminal marked IG feeds B+ to the alternator in KOEO and KOER positions.
Hmmmmm, doesn't look like they ever offered that engine in the States. Shame.
If there are four wires at the field control connector, then I'd expect it to work the same way as that other Toyota you had it for a charging concern. If I remember right, it has two power feeds, one light control circuit, and a load input to the PCM.
Maybe Ivan. I took it as the 3 A terminals were one connector. The B is definitely the + post, and the earth isn't a connector. It's through the housing. My wife's tarago has a 4 pin alternator. It's labelled what the pins are too. Is yours similar?