12V 40A Electric Cooling Fan Relay Wiring Harness Kit with Thermostat Switch 185 On 175 Off
About this item
【Automated Thermal Regulation】- This electric fan relay kit provides automated control for your vehicle's cooling fan, ensuring optimal engine temperatures. The included 3/8" NPT temperature switch is precisely calibrated to activate the fan at approximately 185°F and deactivate it at 175°F. This thermostatic fan control system delivers precision cooling when your engine needs it most.
【Comprehensive Wiring Solution】- The fan wiring kit includes a heavy-duty 12V 40A waterproof relay (JD1912) and a pre-wired harness with a generous 35-inch line length for flexible installation. A 20A blade fuse provides essential circuit protection, and a full set of terminals (RV5.5-10, RV5.5-6, RV1.25-5, BV3.5, FDFD2-250) are supplied for secure connections. This complete fan relay assembly ensures you have all necessary components for a professional setup.
【Robust Electrical Design】- This automotive relay harness utilizes robust 14AWG wires for the main power circuits (PIN30 Red, PIN87 Brown) to effectively handle high-current demands from electric fans. The control circuit wires (PIN85 Black, PIN86 White) are 18AWG, ensuring reliable signal transmission for relay activation. Such heavy-duty wiring specifications contribute to the kit's durability and safe operation under load.
【Simplified System Integration】- A clear wiring diagram is provided, illustrating connections for the battery, fan, ignition, temperature sending unit, and an optional fan override switch. The pre-assembled relay socket and color-coded harness significantly simplify the installation process, reducing setup time and potential errors. This user-friendly relay kit is designed for straightforward integration into most 12V DC automotive cooling systems.
【Broad Cooling Fan Compatibility】- This electric cooling fan relay kit is engineered for compatibility with a wide range of common 10-inch, 12-inch, 14-inch, and 16-inch electric cooling fans. The universal fan controller is suitable for various automotive applications, from classic cars to modern vehicles requiring enhanced cooling performance. Its versatile design makes this an ideal solution for upgrading or repairing vehicle cooling systems.
Spec
| Part NO | JD1912-FAN1 |
| Operating Voltage | 12V DC (Ensure input voltage is ≤12V) |
| Relay Type | JD1912 Waterproof Automotive Relay |
| Relay Rating | 12V 40A |
| Fuse Specification | 20A Blade Fuse (Included) |
| Temperature Switch | 3/8" NPT Thread |
| Activation Temperature | Approximately 185°F (Fan ON) |
| Deactivation Temperature | Approximately 175°F (Fan OFF) |
| Wiring Harness Length | Approximately 35 inches |
| Wire Gauges: | |
| - PIN 30 (Red Wire) | 14AWG (To +12V DC via Fuse) |
| - PIN 87 (Brown Wire) | 14AWG (To Fan Positive) |
| - PIN 85 (Black Wire) | 18AWG (To Temperature Sending Unit / Optional Override Switch Ground) |
| - PIN 86 (White Wire) | 18AWG (To Ignition Switch / Switched +12V Source) |
| Compatible Fan Sizes | Designed for 10", 12", 14", and 16" electric cooling fans |




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