Throughout the history of the automobile, many innovations have come and gone, creating a billion dollar industry with a fierce global market that employs millions. The advancement of the many aspects of technology like computers and electronics have made the modern automobile not only as a mode of transport but also a lifestyle product that caters to many different demographics.

Companies like Swedish automaker Volvo has relied on technology to give their product lines to keep up with the competition. From safety features, CPUs that automate mechanical tasks that were once done manually to entertainment components, the modern automobile may seem a far cry from its ancestor. However, the more things change, the more things stay the same, despite all the innovations, cars still use internal combustion engines, four wheels and its advanced electronic systems are still toggled by relays.

As it strange as it may sound, the simplistic and ancient electric relays are still in use on today's more advance vehicles. In fact, these components are one of the most vital parts of a car. Volvo relays for example, are vital in several systems such as the vehicles lighting system, ignition system and the car's sound system to name a few.

Defined simply as an electrical switch that is toggled by another electrical circuit, relays are usually made up of contacts, springs, armature and electromagnets which in turn isolates a specific electrical circuit from other circuits. The latter two – the armature and electromagnet – make up two independent circuits, with the electromagnet acting as the first circuit controlled by switches. Once the switch is turned on, the second circuit is formed once the electromagnet is charged, thus attracting the armature.

As mentioned earlier, relays are applied to various devices connected to the automobile, but does not necessarily mean that a relay for one device is the same as the others. Again, using Volvo relays as an example, some Volvo models used different voltages, electrical wiring setups and other considerations i.e. a Volvo 240 and a Volvo 780 don't have similar sets of relays. Should the need for replacements of an automobiles old relay come up, it is advised to consult trained professionals in order to pick the correct relay for the particular make and model of the vehicle.