This is wiring diagram to wire the relay for your motorcycle or maybe car for the electric accessories. Why use relay for electric accessories? The most important reason is so that your accessories won’t be ON all the time. Your relay may differ a bit in appearance and terminal numbers. Just make the appropriate substitution. Basically you have to turn the ignition off. Find a place for the relay. Near the battery is good, but it’s also good to have it where it’s accessible. Under the rider’s seat is a reasonable choice for many bikes or make appropriate for cars. Hook some 12-14ga wire with a ring-connector on one end to the +12v (Positive) battery terminal. Hook the other end of the wire with a spade connector to terminal #3 on the relay.
Wiring Diagrams Switch 12 Volt Relay Wiring Diagrams Electric Accessories