* Clock Spring: This is a rotating electrical connector that allows the steering wheel to turn freely while maintaining electrical contact to the controls. The steering wheel controls themselves send signals *through* the clock spring to the next component.
* Wiring Harness: From the clock spring, a dedicated wiring harness carries the signals from the steering wheel controls to the radio's control module (often integrated into the radio head unit itself, or sometimes a separate module). This harness is usually a small, dedicated bundle of wires that connects to both the clock spring and the radio system.
It's important to note that there isn't a direct, single wire connection from each button to the radio. The signals are processed and interpreted by the car's electronic system before reaching the radio. Damage to any part of this chain – the clock spring, the wiring harness, or even the radio's internal control circuitry – can prevent the steering wheel controls from working.
