Car guys and mechanics, this 40 AMP dual electric fan relay kit has everything you need to upgrade your cooling system!

The package includes two 40A relays with wiring harness, a 3/8 inch thermostat switch that kicks fans on at 185°F and off at 175°F, plus a 3/8 to 1/2 inch adapter for different engine sizes.

You also get inline fuse holders, fuses, ring terminals, and connectors - seriously, it's a complete kit.

The wiring diagram makes installation pretty straightforward: red to battery positive, coffee to fan positive, black to ignition, grey to sending unit.

Important note - the thermostat MUST be grounded through the threads to your engine block to work properly.

This setup handles dual 8-16 inch fans perfectly, and the 14AWG wires can handle most applications (though you might want heavier gauge for really high-draw fans).

If you want AC activation control, you'll need an additional relay, but the instructions cover that too.
Perfect for engine swaps, cooling system upgrades, or replacing problematic OEM setups.

Your engine will stay at perfect temperature without any guesswork!