Test diodes of generator - AR15.40-P-9301-02EA

Commercially available tools

Number	Designation
WH58.30-Z-1046-13A	Engine tester with oscilloscope

Fig 1: Generator Connection Diagram - Model 129

Model 129 with engine 119 up to vehicle ident end no. 1F 032 589: Problems with power supply system - test battery voltage-dependent idle speed increase (refer to Diagnosis Manual Engine Volume 2 Group 07.3).

Fig 2: Generator Connection Diagram - Model 163

Fig 3: Generator Connection Diagram - Model 168

Fig 4: Generator Connection Diagram - Model 414

Fig 5: Generator Connection Diagram - Model 170

Fig 6: Generator Connection Diagram - Model 202

Fig 7: Generator Connection Diagram - Model 208

Model 210: as of 1.6.99 a fuse for protection of generator is located in the terminal block circuit 30 (X12/3).

Fig 8: Generator Connection Diagram - Model 210

Connect DC clip-on probe (065) from engine tester with oscilloscope (030) to positive pole of battery (G1)
Start engine.
Switch on low beam.
Assess diode harmonics at 3000 rpm (engine speed).

In this test it is not possible to assess the exciter diodes.

Fig 9: Identifying Harmonics - Negative Diode Defective

Fig 10: Identifying Harmonics - Positive Diode Defective

Fig 11: Identifying Diode Harmonics OK