Carefully calling an alternator a 1 wire as there is a type of alternator that is a 1 wire (it has an internal voltage regulator, no external field wires)
As 67dart273 pointed out
The proper names are:
Grounded field = 1 field terminal
Isolated field = 2 field terminals
1 wire = internally regulated, no external field terminals
Mattax's link in the post 18 does an awesome job at showing the various alternators used in our cars
