Having recently researched the operation of the alternator warning light, I agree with both sierrafery and p76rangie. I think the answer is to disconnect the brown/yellow wire from the alternator and use its terminal as the 12v, engine running-only way to get power to the relay he wants to power (for whatever reason).
'99 DII, STI wires, Champion 7070s, '04 CDL & SLABS, Garvin WILDERNESS rack, painted headliner, air springs victim, headgaskets at 109,000, plus victim of XYZ (twice) and many other ridiculous DII failures. Option B AMIGO FREE since February 2011.
Runs like a top; now if I could just afford the gas! December 2014 update - Wait, I can afford the gas! Drill baby, drill!!!