Brush and brush holder

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

Verify that there is no continuity between each insulated brush and plate using an ohmmeter.
- If there is continuity, replace the brush holder.
  
  Fig 1: Verifying There Is No Continuity Between Each Insulated Brush And Plate Using Ohmmeter
  Courtesy of MAZDA MOTORS CORP.
Measure the brush length.
- If any brush is worn almost to or beyond the minimum specification, replace all the brushes.
  Standard brush length
  
  12.3 mm {0.48 in}
  
  Minimum brush length
  
  7.0 mm {0.28 in}
  
  Fig 2: Measuring Brush Length
  Courtesy of MAZDA MOTORS CORP.
Measure the brush spring force using a spring balance.
- If it is less than the minimum specification, replace the brush spring.
  Standard spring force
  
  21.6 N {2.20 kgf, 4.84 Ibf}
  
  Minimum spring force
  
  5.9 N {0.6 kgf, 1.3 Ibf}
  
  Fig 3: Measuring Brush Spring Force Using Spring Balance
  Courtesy of MAZDA MOTORS CORP.