* Power Source: The lights are connected to your vehicle's electrical system, ultimately drawing power from the battery.
* Switch: A switch (either a physical button or a sensor in the door jamb) controls the circuit. When you open a door (or manually turn on the light), the switch closes the circuit.
* Wiring: Wires run from the power source, through the switch, and to the dome light(s). These wires are usually part of the vehicle's main wiring harness.
* Bulb/LED: The dome light itself (whether it's an incandescent bulb or an LED) completes the circuit, allowing electricity to flow and the light to illuminate.
* Dome Light Module (Possibly): More modern Tahoes might have a dedicated dome light module that manages multiple lights, dimming, and potentially other features (like delayed shut-off). This module acts as an intermediary between the power source and the lights.
In short, when you open a door or activate the switch, you complete an electrical circuit, allowing current to flow from the battery, through the switch, wiring, and finally to the light bulb, causing it to illuminate. If any part of this circuit is broken (blown bulb, faulty switch, damaged wiring, etc.), the light won't work.
