Trailer brake lights work by using a brake light switch that is mounted on the trailer's frame. When the brake pedal is depressed, the switch is activated and power is sent to the trailer's brake lights. The brake lights then illuminate, warning other drivers that the trailer is slowing down or stopping.
Tail lights work in a similar way, but they are activated when the headlights are turned on. The tail lights help other drivers see the trailer at night or in low-light conditions.
