TM 9-4940-568-34
2-12
Table 2-5. Starter Motor Troubleshooting.
Malfunction
Test or Inspection
Corrective Action
1. NORMAL CURRENT AND SPEED.
Cranking motor ok.
Recheck battery, switches and wiring, including battery cable loss check if cranking motor
operation on engine is slow or sluggish (TM 9-4940-568-10).
2. CURRENT FLOW WITH TEST CIRCUIT SWITCH OPEN.
Solenoid switch contacts stuck closed.
Test and, if necessary, replace solenoid assembly (Para 5-23).
3. FAILURE TO OPERATE WITH VERY LOW OR NO CURRENT.
Open solenoid winding.
Inspect and test solenoid assembly (Para 5-23).
Open field circuit.
Inspect and test frame and field assembly (Para 5-23).
Open armature coil(s) or high insulation between commutator bars.
Inspect armature (Para 5-23).
Broken brush spring(s) or worn brushes.
Inspect brushes and brush springs (Para 5-23).
4. FAILURE TO OPERATE WITH HIGH CURRENT.
Frozen bearing or other damage to drive train.
Inspect bearings, armature, drive shaft and related drive parts (Para 5-23).
Direct ground in terminals or fields.
Inspect and test frame and field assembly, solenoid assembly, armature and brush
installations for shorts (Para 5-23).
