1、Simple Wiring: Simplify the wiring of your dual cooling fans with this relay kit. Easy to follow diagram simplifies the connection process for fans. Red wire connects to 12VDC positive battery terminal, brown wire to fan positive, black wire to ignition, and white wire to sender unit. 2、Everything You Need: This electric cooling fan thermostat kit includes a 40A relay, wiring harness, thermostat switch, 2 20amp fuses, 8 ring terminals, and 4 wire connectors. The temperature switch opens the fan at approximately 185°F and closes at 175°F. 3、OE Style Thermostat: The included thermostat must be grounded via threads to the engine and the engine must be grounded. Fits OE style and can be mounted on the engine cylinder head or any water jacket if needed. 4、Additional Wiring for High Spec Fans: If installing high specification fans, larger wires can be crimped or soldered. 14AWG (15A) wires are not sufficient for high current consumption. 5、Universal Compatibility: Ideal for 10, 12, 14, and 16inch cooling fans. To activate the fan when A/C starts, an additional relay kit is needed with specific wiring connections.