If you try to start your vehicle but the motor starter turns over slowly, there are a variety of potential causes. The slow turning doesn't automatically indicate the need to replace your motor starter, but you might require some vehicle maintenance. Fortunately some of it you can do yourself if you know how to use the right tools.
One common cause of a slow turning motor starter is a loose connection to the battery. The loose connection prevents a steady flow of current, needed to get the motor running. Check and tighten the connections and try again. Are you still having trouble? The connections could be corroded or dirty, or you may need to replace the battery cable with a larger type. Sometimes the problem can be caused by a defective or failing starter motor, in which case you will need to have it replaced. One problem not caused directly by the condition of the motor starter is engine timing. If the engine timing is not set properly this may be the culprit. Have this option checked after you have exhausted the simpler possibilities.