Rectifier Diode / Bridge: Testing and Inspection

AR15.40-P-930102P Test diodes of alternator

Commercially available tools:

Connection diagram:

1 Connect the engine tester with oscilloscope (030).
2 Start engine.
3 Switch on low beam.

It is not possible in this test to assess the exciter diodes.

4 Assess diode harmonics at 3000 rpm (engine speed).

Voltage peaks are possible but without meaning:

Harmonics of the diodes is OK (example)
Voltage peaks are possible but without meaning.

Zero line if the prefuse (1) is defective (example):

Zero line if the prefuse (1) is defective (example).

Harmonics, if a positive diode is faulty (example):

Harmonics, if a positive diode is faulty (example).

Harmonics, if a negative diode is defective (example):

Harmonics, if a negative diode is defective (example).