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Armature Test

  1. Check armature insulation. The preferred method uses a 110-volt, 15-watt test lamp. See Fig 1 , Connect the tester between any one commutator segment and shaft. If the lamp illuminates, armature is faulty, and a replacement component is required.
  2. If necessary, the commutator may be machined, providing a finished surface can be obtained without reducing diameter below 28.8 mm (1.13"). Otherwise, a new commutator must be installed. Finish the surface with a fine emery cloth. DO NOT undercut insulation slots.
Fig 1: Testing Armature
G00103056Courtesy of LAND ROVER NORTH AMERICA, INC.