Brush and brush holder

WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata. 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: Checking Continuity Between Insulated Brush And Plate Using An 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
  
  15. 05-20. 35 N {1. 534-2. 076 kgf, 3. 375-4. 567 lbf}
  
  Minimum spring force
  
  5. 9 N {0. 6 kgf, 1. 3 lbf}
  
  Fig 3: Measuring Brush Spring Force Using A Spring Balance
  Courtesy of MAZDA MOTORS CORP.