Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 1064

0.4
0.2
Voltage at
0
alternator
B terminal
- 0.2
- 0.4
ENGINE ELECTRICAL -
NOTE
The voltage waveform of the alternator B terminal can undulate
as shown at left. This waveform is produced when the regulator
operates according to fluctuations in the alternator load
(current), and is normal for the alternator.
In addition, when the voltage waveform reaches an
excessively high value (approximately 2 V or higher at idle),
it often indicates an open circuit due to a brown fuse between
alternator B terminal and battery, but not a defective alternator.
Charging System
16-9
Time