How do you test a relay to see if it is good or bad?

On the Nissan relay there is usually a diagram of the internal workings of the relay. A relay has two windings for the "pull in" windings which will need a power and a ground, on wire to the relay will be direct battery power and when the "pull in" winding receives a power and ground the direct battery power is sent out to the switched load terminal of the relay. Each relay operates differently, you need a wiring diagram or figure out the drawing on the side of the relay.