However, a component with a high current consumption must not be connected using wires which are too thin, or the wires will overheat, blow a fuse, or burn out.
Often, however, it is hidden away, perhaps under the dashboard or down in the front knee-well. The car handbook usually gives the location, but without a book finding the box can prove difficult. Get to know where it is before anything goes wrong.
This type of circuit is called an earth-return system any part of it connected to the car body is said to be earthed.
Most car handbooks and service manuals include a wiring diagram which can be difficult to follow. The colour-coding, however, is a useful guide to tracing wiring.