This key might be helpful to identify the terminals on your alternators, as you can see the same function can have different designations depending on the make and model of alternator

Terminal Definition Notes
A Battery Battery positive connection
B Battery Battery positive connection
B+ Battery Battery positive connection
C Center Centre point of a Y stator
COM Computer Computer Connection
D+ Warning light Comes from the old ‘Dynamo Positive’ on a generator
DFM Dynamo Field Modulation Duty Cycle signal from the ECU
E Warning light Comes from the word ‘Excitation’
F Field For externally regulated alternators
FR Field Regulation Voltage Signal from the ECU
G Ground Chassis negative connection
I Indicator Warning Lamp
L Lamp Warning Lamp
M Field Found on older Externally Regulated units
N Neutral Centre point of a Y-connected stator
P Pulse Stator connection for tachometer
R Relay Output to charge relays, etc
S Sense Battery Voltage sense wire
S (FORD) Stator Stator Pulse. Used for tachometers
T Tach Stator Pulse. Used for tachometers
W Waveform Stator Pulse. Used for tachometers



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