1Simple 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. 2Everything 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 185F and closes at 175F. 3OE 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. 4Additional 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. 5Universal 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. Item Type: Dual Electric Fan Wiring Kit Material: Plastic + Metal Voltage: 12VDC Temperature: About 185F ON, 175F OFF Fitment: Universal product, suitable for 10, 12, 14, and 16 inch cooling fans If you want to turn on the fan when AC is activated, you will need an additional relay kit and follow the steps below: 1. Connect the red wire of the AC relay to the gray wire of the original fan relay harness (signal unit) 2. Connect the gray wire and brown wire of the AC relay to ground 3. Connect the black wire of the AC relay to the +12V of the AC compressor clutch wire 1 x Instruction Manual 2 x 40A Relay with Wiring Harness 1 x Thermostat Switch 2 x 20 Amp Fuse 8 x Ring Terminal 4 x Connector