TROUBLESHOOTING A STARTER MOTOR Troubleshooting a starter motor can be a daunting task, but with the right information, you can quickly identify and resolve the issue. A starter motor's primary function is to spin an engine's crankshaft so that it can start an internal combustion engine. If your car won't start, the most likely culprit is a damaged or malfunctioning starter motor. In this article, we'll guide you through some common problems and offer tips on how to troubleshoot a starter motor.