Standard Waveform
NOTE: The voltage wave-form of the generator B terminal can undulate as shown in the small box. This wave-form is produced when the regulator operates according to fluctuations in the generator load (current), and is normal for the generator.
If the ripple height is extremely high (more than approximately 2 V when the engine is idling), the cause is probably an open circuit between the generator B terminal and the battery due to a blown fuse, and the generator itself is usually okay.