Oscilloscope Patterns and Waveforms

WAVE PATTERN CHECK USING AN OSCILLOSCOPE

MEASUREMENT METHOD







Connect the oscilloscope special patterns pick-up to the generator "B" terminal.

STANDARD WAVEFORM










NOTE: The voltage waveform of the generator "B" terminal can undulate as shown at left. This waveform 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 abnormally high (approximately 2 V or more during idling), the wires between the generator "B" terminal and the battery have broken due to fuse blowing, etc. The generator is usually operating properly.

ABNORMAL WAVEFORMS [2.0L ENGINE]

- Example 1
PROBABLE CAUSE: Open circuit or short circuit in diode







- Example 2
PROBABLE CAUSE: Open circuit in stator coil (In stator coil)







- Example 3
PROBABLE CAUSE: Open circuit in stator coil (Open circuit between stator coil and diode)







- Example 4
PROBABLE CAUSE: Short circuit in stator coil







ABNORMAL WAVEFORMS [2.4L ENGINE]

Example 1
PROBABLE CAUSE: Open circuit in diode







- Example 2
PROBABLE CAUSE: Short-circuit in diode







- Example 3
PROBABLE CAUSE: Open circuit in stator coil







- Example 4
PROBABLE CAUSE: Short-circuit in stator coil