I wired my car (1990 CRX Si) as such:
Remove the large white wire from the alternator (output wire) and from the main fuse panel in the engine compartment. You can remove this wire completly from the wiring harness if you wish, I did, in order to ensure that it did not splice or "t" to any other circuits. It didn't.
Remove the stock battery (+) cable that goes from the battery to the main fuse panel and to the starter. Disconnect all three connections. Again, discard, if you wish. I removed the crimp on battery terminal from this wire and re-used it.
Install a white wire (or any colour you wish) from the alternator to one side of the disconnect switch. I used #10 wire, 12 or 14 is probably fine.
To the same side of the disconnect switch, run a red wire from the positive battery terminal. I used #6 wire, #8 is likely OK, Honda starters don't require a lot of juice.
From the OTHER side of the disconnect switch, run another large red wire to the starter.
From the starter, run another short wire (#10 is likely fine, I used #6) to the main fuse panel and connect it to the left terminal. This terminal is fused through the 60a main fuse, the other one (now unused) is not fused through the main fuse.
That does it!
To summarize, both possible sources of power (battery and alternator) are disconnected and isolated from the rest of the car through the switch. Any consumer of power, including alternator excitation, fuel pump, ignition, etc. is completely cut off by the switch.
Also, there is a path for the alternator current to flow to (momentarily) when you activate (move to OFF position) the switch, through the battery, which protects the alternator diodes.
I think that's it...[/b]
