This 3-speed wire harness is supplied by the original manufacturer for use in ceiling fans. It is an electrical component that connects the ceiling fan motor to the fan speed switch to allow the user to control the speed settings. Over time the wire harness may become faulty due to physical damage, loose connections, or electrical failure...Read mores. If it fails, you will likely be unable to adjust the speed settings, or the fan may not run at all. Before beginning this repair, turn off the power to the fan at the circuit breaker. Remove the fan blades and any other parts blocking access to the electrical components. Locate the wire harness which is connected to the fan motor and speed switch or control panel (depending on your model) and take a picture of how the wires are routed for the installation. Disconnect the wire connectors and remove the faulty harness. Position the new wire harness in the appliance and connect the wires to the appropriate terminals using the image you captured. Reassemble the fan parts. Turn on the power and test the fan speed settings to ensure that the new wire harness is functioning.