See All 8 Photos If you are unsure which wire is which coming out of the electric fan, find the fan manufacturer's supplied wiring diagram ... Way to Hook Up a Relay to 12 Volt Power While ...

Love it or hate it, wiring is a part of any project car ... Once you activate the relay with 12V power and ground, the relay will power the accessory. A relay is essentially a heavy-duty switch ...

As you can see in the schematic the 12V battery (or use other voltages ... When voltage is applied to the coil then the relay switches and now T1 (plus) is connected to contact 2 (and 3) and T2 (minus ...