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Cummins/Onan A15 — Testing the Main Rotor (Generator Field)

Testing & diagnosis

For the Cummins/Onan A15, from the Cummins/Onan service manual.

Applies to: Cummins/Onan DGBB, Cummins/Onan DGBC, Cummins/Onan DGCA, Cummins/Onan DGCB, Cummins/Onan DGCC, Cummins/Onan DGDA, Cummins/Onan DGDB, Cummins/Onan DGEA, Cummins/Onan DGFA, Cummins/Onan DGFB, Cummins/Onan B and C Series diesel engine

Procedure

  1. Disconnect the two main rotor leads from the rotating rectifier assembly.
  2. Measure resistance between the two leads with Wheatstone bridge or digital ohmmeter.
  3. Replace rotor if resistance not per Table 7-1.
  4. Reconnect rotor leads and torque terminals to 24 in-lbs (2.7 Nm).

Tools required

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

  • terminal torque 24 in-lbs (2.7 Nm)

Full service-parts list: Cummins/Onan DGBB →, Cummins/Onan DGBC →, Cummins/Onan DGCA →, Cummins/Onan DGCB →, Cummins/Onan DGCC →, Cummins/Onan DGDA →, Cummins/Onan DGDB →, Cummins/Onan DGEA →, Cummins/Onan DGFA →, Cummins/Onan DGFB →

Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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