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Diode Assembly

  1. Place ohmmeter on x100 scale. Connect ohmmeter leads across "B+" terminal and, in turn, to each of the 3 stator terminals. Reverse leads. Ohmmeter should indicate continuity in one direction only.
  2. Connect ohmmeter leads across negative plate and, in turn, to each of the 3 stator terminals. See Fig 1. Reverse leads. Ohmmeter should indicate continuity in one direction only.
  3. Connect ohmmeter leads across "D+" terminal and, in turn, to each of the 3 stator terminals. Reverse leads. Ohmmeter should indicate continuity in one direction only. Replace diode assembly if defective.
Fig 1: Testing Bosch Diode Assembly
G29438Courtesy of BMW OF NORTH AMERICA, INC.