Alternator "buzzing" or "humming" when car is off, battery dies

[69LT1Nova]

im using a stock alternator from an 89 iroc which is a 4 pin plug I believe but I only have the main battery cable running to the stud of coarse and one ignition wire running to the 4wire plug. and it works fine, no load sensing wire and no 'low voltage' to dashboard wire.

Sounds like this works!

Hopefully it works for me too...