You can't count just how many relays there are in your vehicle because of their great number. You have relays controlling the safety features in your car (the ABS system, the airbags, and the anti-theft alarm), your various car lights (the headlights and fog lights, as well as the turn signals and the parking lights), and other basic functions that enable your car to run well (glow plugs and cruise control). All of these relays work the same way, only they power different parts.
Two General Types of Relay
Although there are different relays in your vehicle, these parts can only be generally categorized into two, as follow:
What it is: This is a relay that receives low voltage signal across its terminals and then converts the fluctuations created by such signals into a mechanical force that actuates the relay's electrical contacts.
Advantages: This type of relay is relatively cheap. Using it is also easy, so there's no hassle involved.
Disadvantages: This relay is mechanical in nature, and it is that which serves as its weakness. It doesn't respond as quickly and it may have a shorter life because of its wear components.
Solid State relay
What it is: This relay operates in the same manner, only that it isn't mechanical in nature. It is purely electrical, and it is composed of a transistor instead of moving parts.
Advantages: This type of relay has faster response time. It is also highly reliable, and it generally features a longer service life.
Disadvantages: Despite the many benefits, the solid state relay also has some disadvantages. One of the most common is its susceptibility to overheating.
Under these two general types of relay, there are still other relay designs, some of which are in popular use today while others have already become rare. If you're looking for a new relay for your vehicle, you might want to consider the different types available. Find one that is compatible with your vehicle make and model to ensure efficient function.