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Generator & Regulator Switch

Check for correct connections on fully charged battery, generator and starter motor. Check for good ground connection between engine and body. Check for properly tightened drive belt. Connect DIS tester. Search down through the following menus:

Work through test modules. To diagnose oscillograms for each fault, see GENERATOR OSCILLOGRAMS  . If generator is faulty, repair or replace it. To replace, see GENERATOR  under REMOVAL & INSTALLATION.

GENERATOR OSCILLOGRAMS

Fault Oscillogram
Fault-Free See Fig 1
One Phase Interrupted See Fig 2
Internal Fault See Fig 3
Open Circuit In Negative Diode See Fig 4
Short Circuit In Positive Diode See Fig 5
Open Circuit In Positive Diode See Fig 6
Open Circuit In Exciter Diode See Fig 7
Fig 1: Identifying Oscillogram For A Fault-Free Generator
G00301749Courtesy of BMW OF NORTH AMERICA, INC.
Fig 2: Identifying Oscillogram For One Phase Interrupted
G00301750Courtesy of BMW OF NORTH AMERICA, INC.
Fig 3: Identifying Oscillogram For Internal Fault
G00301751Courtesy of BMW OF NORTH AMERICA, INC.
Fig 4: Identifying Oscillogram For Open Circuit In Negative Diode
G00306585Courtesy of BMW OF NORTH AMERICA, INC.
Fig 5: Identifying Oscillogram For Short Circuit In Positive Diode
G00306586Courtesy of BMW OF NORTH AMERICA, INC.
Fig 6: Identifying Oscillogram For Open Circuit In Positive Diode
G00306587Courtesy of BMW OF NORTH AMERICA, INC.
Fig 7: Identifying Oscillogram For Open Circuit In Exciter Diode
G00306588Courtesy of BMW OF NORTH AMERICA, INC.
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