How Do I Tell if the Starter Solenoid Is Bad on My Kohler Riding Mower Engine?

Place the negative lead of a voltmeter onto the negative battery terminal. Place the positive lead of the voltmeter onto the positive terminal. The voltmeter should read at least 12.5 volts. If the voltmeter reads less, charge the battery with a battery charger. If the engine still does not turn over after charging the battery or the battery has adequate charge, move to the next step.

Turn on the mower's headlights and turn the ignition key. If the lights do not dim, the ignition is likely the issue since it is not sending power to the solenoid. If the lights dim, it indicates the ignition key is sending power to the starter solenoid, so move to the next step.

Place the mower in neutral and set the parking brake. Disengage the mower deck. Turn the ignition key on so the headlights turn on.

Locate the two large terminal posts on the starter motor. The starter motor mounts to the side of the engine. It is approximately 6 inches in length and looks like a metal cylinder. It has a smaller cylinder mounted to it. The smaller cylinder is the starter solenoid.

Place the metal shaft of a screwdriver so it touches both terminal posts on the starter motor at once. This shorts out the solenoid and creates a direct connection between the ignition and the starter motor. If the starter motor turns on and starts to run, it indicates a defective solenoid. If the starter motor fails to turn on, the starter motor is defective.