Automotive relays are an integral part of a vehicle's electromechanics. They are used in a multitude of areas, including lights, door locks, air conditioners and more. They have a few more components than a simple electric relay and contain an outer casing, followed by insulation, which protects a coil and metal core. There is also a yoke, a spring, an armature, a bonding strap and contact points.
The spring, core and yoke make the first circuit, whilst the contact point, armature and contact points make up the second circuit. The function of the relay works the same in that a current is passed through the first circuit, which causes the yoke and core to pull the armature and create a current in a second circuit. However, the function of an Automotive relay is extended beyond an on/off mechanism, by the fact that there are contact points beyond the armature, meaning that currents can be directed to different circuits depending on what current is passing through the first circuit.