john deere 111h charging issue

hope that someone can help me with this one.
i bought the mower this spring and it hasnt been charging.
the tractor has been repowered with a 12 hp B/S by someone else.
the output wire from the stator was never hooked up.
with a dmm on the wire i get a A/C voltage between 13 volts and 27 volts
depending on rpm.
what do i need for a voltage regulator or rectifier as none of this is still on the tractor.
the output wire is a single wire with a black round quick connect.
thanks for any input

get the model, type, and code off the engine and post it so we can give you more info. Normally the regulator, retifier engine have a two wire alternator which makes me think that the diode may be bad if you are reading ac voltage.

12 HP B/S engine
the model # 284707,
type # 1026-e1,
code# 980116ZA
I have looked on the B/S site but there seem to be mant different output wiring types
depending on year of build etc,
from a diagram in a clymers manual it looks like a single wire output has a built in diode
but when i test the wire for DC voltage i get 0 volts
hope you guys can steer me in the right direction
thanks