Starter Motor: Testing and Inspection

INSPECTION




1. INSPECT MAGNETIC SWITCH ASSEMBLY
a. Check the plunger.
1. Push in the plunger and check that it returns quickly to its original position.
If necessary, replace the magnetic switch assembly.




b. Check if the pull-in coil has an open circuit.
1. Check the resistance between terminals 50 and C.

Resistance: Below 1 Ohm

If the result is not as specified, replace the magnetic switch assembly.




c. Check if the hold-in coil has an open circuit.
1. Check the resistance between terminals 50 and the switch body.

Resistance: Below 2 Ohms

If the the result is not as specified, replace the magnetic switch assembly

2. INSPECT STARTER ARMATURE ASSEMBLY
a. Check the commutator for contamination and burns on its surface.
If the surface is dirty or burnt, correct is with sandpaper (No. 400)or a lathe.




b. Check if the commutator has an open circuit.
1. Check the resistance between the segments of the commutator.

Resistance: Below 1 Ohm

If the result is not as specified, replace the armature assembly.




c. Check if the commutator is grounded.
1. Check the resistance between the commutator and armature coil core.

Resistance: 10 kOhms or higher

If the result is not as specified, replace the armature assembly.




d. Using a vernier caliper, measure the commutator's depth.

Specified depth: 3.1 mm (0.122 in.)
Maximum depth: 3.8 mm (0.150 in.)

If the depth is greater than the maximum, replace the starter armature.




3. INSPECT STARTER COMMUTATOR END FRAME ASSEMBLY
a. Using a vernier caliper, measure the brush length.

Specified length: 9.0 mm (0.354 in.)
Maximum length: 4.0 mm (0.157 in.)

If the length is less than the minimum, replace the end frame assembly.




b. Check the brush insulation.
1. Check the resistance between the positive (+) and negative (-) brush.

Resistance: 10 kOhms or higher

If the result is not specified, repair or replace the end frame assembly.




4. INSPECT STARTER DRIVE HOUSING ASSEMBLY
a. Check the starter clutch.
1. Rotate the clutch pinion gear counterclockwise and check that it turns freely. Try to rotate the clutch pinion gear clockwise and check that it locks.
If necessary, replace the drive housing assembly.