70 Amp. Fan Relay System for Slim Line Super Duty Fans Stand Alone, NO A-C Req., On @ 176, Off @ 161 The new generation of shrouded, slim-line "super-duty" fans from Cooling Components and Walker are made to fit in places where no other shrouded electric cooling fan will, but their monster motors draw some heavy amperage. RON FRANCIS WIRING, America's leading developer of innovative electrical products, has the controller and relay you'll need to run one of these fans. The Super-Duty Fan Controller from RON FRANCIS WIRING packages the company's standard 176-degree "on" / 161-degree "off" sensor with a large capacity 70-amp power relay for completely safe and efficient operation. This unit has a highly reliable thermostat. Sensor has a 3/8" pipe thread. Relay protection is critical to all cooling fan installations, and the amperage load should always be isolated from the ignition switch. Just follow the easy instructions and you'll be wired the right way. Note: Replacement sensor is our part number AR-33.