Starter Motor: Testing and Inspection
INSPECTION1. INSPECT ARMATURE COIL
a. Check the commutator has an open circuit.
Using an ohmmeter, check that there is continuity between the segments of the commutator.
If there is no continuity between any segments, replace the armature.
b. Check the commutator for ground.
Using an ohmmeter, check that there is no continuity between the commutator and armature coil core.
If there is continuity, replace the armature.
2. INSPECT COMMUTATOR
a. Check whether the commutator surface is dirty or burnt.
If the surface is dirty or burnt, correct it with sandpaper (No.400) or a lathe.
b. Check the commutator circle runout.
1. Place the commutator on V-blocks.
2. Using a dial gauge, measure the circle runout.
Maximum circle runout: 0.05 mm (0.0020 in.)
If the circle runout is greater than the maximum, correct it on a lathe.
c. Using vernier calipers, measure the commutator length.
Standard length: 3.3 mm (0.1299 in.)
Maximum length: 4.0 mm (0.1575 in.)
If the length is greater than the maximum, replace the armature.
3. INSPECT COMMUTATOR END FRAME ASSY
a. Check the brush holder insulation.
Using an ohmmeter, check that there is no continuity between the positive (+) and negative (-) brush holders.
If there is continuity, repair or replace the starter commutator end frame assy.
b. Using vernier calipers, measure the brush holder length.
Standard length: 9.0 mm (0.3543 in.)
Minimum length: 4.0 mm (0.1575 in.)
If the length is less than the minimum, replace the starter commutator end frame assy.
4. INSPECT CLUTCH AND GEAR
a. Check the gear teeth on the planetary gear, internal gear and clutch assembly for wear or damage.
If damaged, replace the planetary gear or starter housing with clutch assy.
If damaged, also check the drive plate ring gear for wear or damage.
b. Check the clutch pinion gear.
Rotate the clutch pinion gear clockwise, and check that it turns freely. Try to rotate the clutch pinion gear counterclockwise and check that it locks.
If necessary, replace the starter housing with clutch assy.
5. INSPECT MAGNETIC SWITCH
a. Check the plunger.
Push in the plunger and check that it returns quickly to its original position.
If necessary, replace the magnetic switch.
b. Check whether the pull-in coil has an open circuit.
Using an ohmmeter, check that there is continuity between terminals 50 and C.
If there is no continuity, check and replace the magnetic switch.
c. Check whether the hold-in coil has an open circuit.
Using an ohmmeter, check that there is continuity between terminal 50 and the switch body.
If there is no continuity, replace the magnetic switch.
TEST
NOTE: These tests must be performed within 3 to 5 seconds to prevent the coil from being burnt out.
1. DO PULL-IN TEST
a. Disconnect the lead wire from terminal C.
b. Connect the battery to the magnetic switch as shown. Check that the clutch pinion gear moves outward.
2. DO HOLDING TEST
With battery connected as shown above with the clutch pinion gear out, disconnect the negative (-) lead from terminal C.
Check that the pinion gear remains out.
3. INSPECT CLUTCH PINION GEAR RETURN
Disconnect the negative (-) lead from the switch body.
Check that the clutch pinion gear returns inward.
4. DO NO-LOAD PERFORMANCE TEST
a. Connect the battery and ammeter to the starter as shown.
b. Check that the starter rotates smoothly and steadily with the pinion gear moving out.
Check that the ammeter shows the specified current.
Specified current: 90 A or less at 11.5 V