Relays

4 pin relay

Relay base layout:

connectors:

85 - coil negative

86 - coil positive

30,87 - Switch terminals (in 4pin relay 30 to 87 is NO( normally open))

5 pin Relay

Base Layout:

connectors:

85 - coil negative

86 - coil positive

30,87 - Switch terminals (NO( normally open))

30, 87A - Switch terminals (NC (normally closed))

using relays create a circuit which output two independent positive from one alarm negative

ver1

Ver2 suggested by Carl

relay in circuit powering Light Bulb.

relay in hi/low beam switching

Set of 4pin relays powering the window motor

another version suggested by Kit using two 5 pin relays

  

to prevent circuit components from back emf produced by inductor (relay coil) the diode is installed.

some automotive relays already come with built in diode.