Electrical

Starter Inspection [Mzr 2.0, Mzr 2.5]

~4min read
On-vehicle Inspection

1. Verify that the battery is fully charged.

2. The starter is normal if it rotates smoothly and without any noise when the engine is cranked.

  • If the starter does not operate, inspect the following:

    • Remove the starter, and inspect the starter unit.

    • Inspect the related wiring harnesses, the ignition switch, and the transaxle range switch (ATX) or starter interlock switch (MTX).

No-load Test

1. Verify that the battery is fully charged.

2. Connect the starter, battery, and a tester as shown in the figure.


3. Operate the starter and verify that it rotates smoothly.

  • If the starter does not rotate smoothly, inspect the starter unit.

4. Measure the voltage and current while the starter is operating.

  • If not within specification, replace the starter.

    Starter no-load test voltage
  • 11 V

    Starter no-load test current
  • MZR 2.0 : 95 A or less

  • MZR 2.5 : 90 A or less

Magnetic Switch Operation Inspection Pull-out test NOTE:
  • Depending on the battery charge condition, the starter motor pinion may rotate while in an extended state. This is due to current flowing to the starter motor through the pull-in coil to turn the starter motor, and does not indicate an abnormality.

1. Verify that the starter motor pinion is extended while battery positive voltage is connected to terminal S and the starter body is grounded.


  • If the starter motor pinion is not extended, repair or replace the starter.

Return test

1. Disconnect the motor wire from terminal M.

2. Connect battery positive voltage to terminal M and ground the starter body.


3. Pull out the drive pinion with a screwdriver. Verify that it returns to its original position when released.

  • If it does not return, repair or replace the starter.

Pinion Gap Inspection

1. Pull out the drive pinion with the battery positive voltage connected to terminal S and the starter body grounded.


CAUTION:
  • Applying power for more than 10 s can damage the starter. Do not apply power for more than 10 s.

2. Measure the pinion gap while the drive pinion is extended.


  • If not as specified, adjust with an adjustment washer (between drive housing front cover and magnetic switch).

    Starter pinion gap
  • 0.5—2.0 mm {0.02—0.07 in}

Starter Inner Parts Inspection Armature

1. Verify that there is no continuity between the commutator and the core at each segment using a tester.


  • If there is continuity, replace the armature.

2. Verify that there is no continuity between the commutator and the shaft using a tester.


  • If there is continuity, replace the armature.

3. Place the armature on V–blocks, and measure the runout using a dial indicator.


  • If not within specification, replace the armature.

    Starter armature runout
  • 0.1 mm {0.004 in} max.

4. Measure the commutator diameter.


  • If not within the minimum specification, replace the armature.

    Starter commutator diameter
  • Standard: 29.4 mm {1.16 in}

  • Minimum: 28.8 mm {1.13 in}

5. Measure the segment groove depth of the commutator.


  • If not within the minimum specification, undercut the grooves to the standard depth.

    Segment groove depth of starter commutator
  • Standard: 0.5 mm {0.02 in}

  • Minimum: 0.2 mm {0.008 in}

Magnetic switch

1. Inspect for continuity between terminals S and M using a tester.


  • If there is no continuity, replace the magnetic switch.

2. Inspect for continuity between terminal S and the body using a tester.


  • If there is no continuity, replace the magnetic switch.

3. Verify that there is no continuity between terminals M and B using a tester.


  • If there is continuity, replace the magnetic switch.

Brush and brush holder

1. Verify that there is no continuity between each insulated brush and plate using a tester.


  • If there is continuity, replace the brush holder.

2. Measure the brush length.


  • If any brush is worn almost to or beyond the minimum specification, replace all of the brushes.

    Starter brush length
  • Standard: 12.3 mm {0.484 in}

  • Minimum: 5.5 mm {0.22 in}

3. Measure the brush spring force using a spring balance.


  • If not within the minimum specification, replace the brush and brush holder component.

    Starter brush spring force
  • Standard: 15.1—20.4 N {1.54—2.08 kgf, 3.40—4.58 lbf}

  • Minimum: 2.75 N {0.280 kgf, 0.618 lbf}

Test yourself

A quick Mazda 3 quiz: every answer comes with an explanation and a link to the manual page.