I think we are mixing up some terminology here - maybe I'm screwing things up here, but I was calling the brown wire the exciter wire, which "turns on" the alternator.
I do have full voltage at the red wire - and on my car a feed comes direct from the POS battery cable to the BATT terminal on the alternator, with a short loop to the alternator connecter (as you describe the 87/88's). It's the brown wire where I have the extremely low votlage, causing the alternator not to charge.
1985 Chevrolet Monte Carlo SS
5.7 LITRE / TES Headers / SShaker Hood / WC T-5 5-Speed1970 Pontiac GTO
Orbit Orange Judge Re-creation / YZ RAIII 400 / M21 4-Speed