How do you test a starter motor to determine if it is functioning properly?

• A. Check battery voltage at the starter solenoid, listen for a solid engage, measure current draw, and inspect for corrosion; verify engine cranks.
• B. Verify engine cranks by turning the key and listening for a successful engagement, assuming battery is healthy.
• C. Inspect the starter housing for cracks and replace if cracked.
• D. Replace the starter motor without any testing.

Answer: (B)

The essential test is to observe whether the engine actually cranks when you operate the starting system, assuming the battery is healthy. If turning the key produces a solid, consistent crank and the engine begins to rotate smoothly, you’ve confirmed the starter motor, its solenoid, and the starting circuit are delivering the necessary power and engagement. This direct indication of performance tells you the starter is doing its job and the mechanical path from the battery to the flywheel is functioning.

Visual checks like inspecting the starter housing don’t prove operation, and replacing the starter without testing wastes time and can miss other causes of a no-crank condition (such as battery, cables, grounds, or the ignition switch). If cranking doesn’t occur, you’d diagnose the actual starting circuit and power path rather than assuming the starter is bad.