Starter Motor: Testing and Inspection

To obtain full performance data on a starter motor, or to determine the cause of abnormal operation, the starter motor should be submitted to a no-load and torque test. This test is best performed with the starter mounted on a starter bench tester.
However, a simple torque test may be made quickly with the starter in the car. Make sure the battery is fully charged and the starter circuit wiring and terminals are in good condition. Then operate the starter to see if the engine turns over normally. If it does not, the torque developed is below standard and the starter should be removed for further testing.