Permanent magnet alternator wiring

[timbatrader]

I have replaced several generators and externally regulated alternator's on old tractors with modern two wire alternators simple one wire to the battery and second to the key switch via the charge light on the dash a neighbour has asked for help with his tractor which a standard car alternator will not fit but has got hold of an internally regulated permanent magnet alternator that will physically fit but it has four wires coming out. can anyone help as to how to wire this up ?
my guess being permanent magnet it will not need current from the key switch to excite coil does all it need the big single wire connected either before or after the key switch to the battery?
KOKUSAN DENKI: GP9905

ITEM DESCRIPTION: ALTERNATOR
UNIT TYPE: ISUZU
VOLTAGE: 12
AMPERAGE: 20
REGULATOR: INTERNAL
POLARITY: NEGATIVE
SPECIFICATIONS: PERMANENT MAGNET
NOTES: (1) THREADED & (1) UNTHREADED MOUNTING EAR
WEIGHT: 5.61 LBS / 2.55 KG

 

[Agvg]

https://www.google.com/url?sa=t&sou...Vaw3C2G-a6_kua5rsXdc5slEm&cshid=1552623175160

Is this of any help?