It’s a sound with which most drivers are all too familiar. As they make a turn, they’ll hear the subtle click click click of a turn signal. But very few drivers probably know how that sounds gets produced. The team at Jalopnik decided to take apart two different styles of turn signals to show viewers how they work.
The two cars, obviously, had differing turning devices. The short answer for the first car is a bimetallic spring from the flasher found in the Jeep causes the clicking. The top part of the metal bends the spring until it hits the bottom and completes the circuit.
However, in a Volkswagen Beetle, the sound is controlled by an integrated circuit chip that controls the current to the relay and, thus, makes the clicking.