The clicking sound you hear when you use your turn signal is actually just a relay. A relay is an electromagnetic switch that is activated by an electrical current. The clicking sound is simply the coil inside the relay switching on and off.
The reason your turn signal makes a clicking noise has to do with how it works. Your car’s turn signals use what’s called a flasher unit, which contains two sets of contacts that complete an electrical circuit. When one set of contacts opens and the other closes, it completes the circuit and activates your bulb.
The problem is that these contacts can get worn down over time, causing them to not make good contact with each other anymore. This results in a poor connection, which will cause your bulbs to dim or even go out entirely. In order to solve this problem, manufacturers came up with the idea of using a relay in conjunction with the flasher unit.
A relay is basically just an electrically-activated switch. When current passes through the coil inside the relay, it creates a magnetic field that activates the switch and completes the circuit. This ensures that there is always a good connection between the contacts, regardless of how worn down they may be getting.
So there you have it! The next time you’re wondering why your turn signal is making that annoying clicking noise, just remember that it’s actually doing its job – keeping those bulbs nice and bright so you can stay safe on the roadways!