The most common method involves using two specific relays or contactors that allow for polarity reversal. Ensure the input and output terminals are clearly marked for accurate connection. A reversing switch allows the user to change the direction of current flow in a circuit, effectively reversing the rotation direction of a motor. So, how do you wire a polarity reversing switch? It's not as complicated as it may seem. All the wiring diagrams use shows examples of switNow, to reverse the motor's rotation, swap the connections of two of the incoming power lines (for example, interchange the wires at L2 and L3). After making the changes, double-check each connection for tightness and proper. Reversing switches are an essential and versatile piece of hardware for anyone who works with electrical systems.