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

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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

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Fig 3: Generator Connection Diagram - Model 168

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Fig 4: Generator Connection Diagram - Model 414

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Fig 5: Generator Connection Diagram - Model 170

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Fig 6: Generator Connection Diagram - Model 202

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Fig 7: Generator Connection Diagram - Model 208

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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

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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

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Fig 10: Identifying Harmonics - Positive Diode Defective

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Fig 11: Identifying Diode Harmonics OK

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