Every coolant fan switch in our offering is a direct-fit replacement, manufactured to the exact resistance and temperature ratings as the OE, to ensure switching at the correct temperature to keep cooling systems functioning properly. This switch is engineered to carry a high electric current in order to send the message to increase or decrease airflow for temperature control to prevent engine shutdown due to overheating. Our switches are made using only the most durable materials, such as metal housings and high temperature wire covers to ensure that you receive a longer lasting part. Robust design and high grade materials meet the stringent demands of today's service professional. In design, we specify custom wax formulations that will expand when heated, activate a snap action electrical contact and transfer the electrical signal to the fan controller.