Starter Motor: Testing and Inspection
STARTER INSPECTIONOn-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 transmission range switch (AT).
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 the specification, replace the starter.
Magnetic Switch Operation Inspection
Pull-out test
NOTE: In case the battery is being charged, the pinion may turn during a protruded state. This is normal because the current flows to the motor through the pull-in coil and the motor turns.
1. Verify that the drive pinion is pulled out with battery positive voltage connected to terminal S and the starter body grounded.
- If not pulled out, 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 does not return, repair or replace the starter.
Pinion Gap Inspection
1. Pull out the drive pinion with 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 the aforementioned time.
2. Measure the pinion gap while the drive pinion is pulled.
- If not as specified, adjust with an adjustment washer (between drive housing front cover and magnetic switch).
Pinion gap
AT: 0 mm {0 in}
MT: 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 an ohmmeter.
- If there is continuity, replace the armature.
2. Verify that there is no continuity between the commutator and the shaft using an ohmmeter.
- If there is continuity, replace the armature.
3. Place the armature on V-blocks, and measure the runout using a dial indicator.
Runout
0.05 mm {0.002 in} max.
4. Measure the commutator diameter.
- If not within the minimum specification, replace the armature.
Standard commutator diameter
29.4 mm {1.16 in}
Minimum commutator diameter
28.8mm {1.13 in}
5. Measure the segment groove depth of commutator.
- If not within the minimum specification, undercut the grooves to the standard depth.
Standard depth
0.4 - 0.6 mm {0.016 - 0.023 in}
Minimum depth
0.2 mm {0.008 in}
Magnetic switch
1. Inspect for continuity between terminals S and M using an ohmmeter.
- If there is no continuity, replace the magnetic switch.
2. Inspect for continuity between terminal S and the body using an ohmmeter.
- If there is no continuity, replace the magnetic switch.
3. Verify that there is no continuity between terminals M and B using an ohmmeter.
- 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 an ohmmeter.
- 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 the brushes.
Standard brush length
AT: 17.5 mm {0.69 in}
MT: 12.3 mm {0.48 in}
Minimum brush length
AT: 12.0 mm {0.47 in}
MT: 7.0 mm {0.28 in}
3. Measure the brush spring force using a spring balance.
- If not within the minimum specification, replace the brush spring.
Standard spring force
AT: 23.3 - 31.7 N {2.38 - 3.23 kgf, 5.24 - 7.12 lbf}
MT: 18.3 - 24.9 N {1.87 - 2.53 kgf, 4.12 - 5.59 lbf}
Minimum spring force
AT: 10.0 N {1.02 kgf, 2.25 lbf}
MT: 5.9 N{0.6 kgf, 1.3 lbf}