This guide shows you how to replace a damaged Start Switch on a typical single speed A.O. Smith motor. This Start Switch is only used with motors that have a start circuitry to boost starting torque. See our overview guide on "How To Replace AO Smith Motor Parts - Overview" to see how the Start Switch operates with the other electrical components. Although this guide is written for an A.O Smith single speed, many of the steps are applicable to other models and speeds.