Starting/Charging Systems (H4SO): Starter: Inspection: Armature
- Check the commutator for signs of seizure or stepped wear caused by roughness of the surface. If it has minor wear, correct it by using sand paper (#300).
- Run-out test
Check for run-out on the commutator. If excessive, replace it.
Commutator run-out:
Standard
3.1 mm (0.1220 in)
Service limit
3.8 mm (0.1496 in) or less
- Armature short-circuit test
Place the armature on the growler tester to check for short circuits. Hold an iron sheet (thickness gauge, etc.) against the armature core while slowly rotating the armature. If the circuit of the armature is shorted, the steel seat will vibrate, causing it to move towards the core. When the steel seat has moved or vibrated, replace or repair the armature with the shorted circuit.
- Armature discontinuity test
Using a circuit tester, touch one probe to the armature and the other to commutator. If there is no continuity, it is normal. If there is continuity, the armature is grounded.
If grounded, replace the armature.