Engine: Can't Turn Engine Off

The switch turns the power off at the ignition module to stop the current flowing to the spark plug. When the switch is in the on position, the current will flow. If you cannot shut the engine down with the switch, it most likely means that the switch is malfunctioning. To inspect and repair the switch, first remove it from its housing (this step may vary depending on your engine model). Once you have the switch removed, check that all the wires are intact where they connect to the switch, as well as at the ignition module. Remove the switch and disconnect the wires, then check the switch with an ohmmeter for continuity. The readings on the ohmmeter should be different when the switch is in the on position than when it is in the off position. If the reading stays the same for both positions, the switch is faulty. When you discover a faulty switch, you will need to install a new one.