* Horn: Activated by a switch in the steering wheel. This switch completes a circuit, sending power to the horn itself.
* Brake Lights: Activated by a switch within the brake pedal assembly. When you press the brake, this switch completes a circuit, sending power to the brake lights.
* Turn Signals: Controlled by a turn signal switch (usually a lever on the steering column). This switch sends power to the appropriate turn signal lights (left or right) sequentially, via a flasher unit that provides the intermittent blinking action.
Shared Components (but independent function):
* Power Source: All three systems ultimately draw power from the battery.
* Fuses: There are likely separate fuses protecting the circuits for each system. A blown fuse could disable one system without affecting the others.
* Grounds: Good electrical grounding is crucial for all three to work. A poor ground could affect one or all of the systems.
* Wiring Harness: The wiring harness routes the power and ground connections to the various components. Damage to the harness in a specific area could affect multiple systems.
Why they might *seem* related if something goes wrong:
If a problem develops, it *might* affect multiple systems. For example:
* Blown Fuse: A blown fuse in the power supply for a shared section of wiring could disable all three.
* Wiring Issues: A short circuit or damaged wiring in the common ground could interfere with all three.
* Bad Multi-Function Switch (Steering Column Switch): This switch might control more than just the turn signals. If it's failing, it could affect turn signals, and possibly other functions.
In short: They are separate systems with some shared infrastructure, but their operation is independent. If you're having problems with one or more of these, tracing the circuits and checking fuses and grounds is the best way to troubleshoot.
