Mmmm actually I remember have seen this acc being sourced in the batt side of the ammeter on diagrams, straight at the amm stud, but is a puntual power source moment, not a constant sucker.BTW, the optional factory power window relay and circuit breaker is connected to the alternator side ammeter stud on most of these cars from the time, not anywhere on the battery side of the ammeter. Once more, there are/were no factory operating loads at the battery or anywhere between the battery and the ammeter originally, by design.
Could I be wrong? Maybe but is just what I remember right now.