Stoplight System

equipped vehicles is combined with the neutral safety switch. Figure 2-70.—Turn signal flasher. pedestrians, whenever the vehicle is shifted into reverse. The backup light system has a fuse, gearshift- or transmission-mounted switch, two backup lights, and wiring to connect these components. The backup light switch closes the light circuit when the transmission is shifted into reverse. The most common backup light switch configurations are as follows: The backup light switch mounted on the transmission and operated by the shift lever. The backup light switch mounted on the steering column and operated by the gearshift linkage. The transmission- or gearshift-mounted backup light switch on many automatic transmission- STOPLIGHT SYSTEM All vehicles that are used on public highways must be equipped with a stoplight system. The stoplight system consists of a fuse, brake light switch (fig. 2-71), two rear warning lights, and related wiring. The brake light switch on most automotive equipment is mounted on the brake pedal. When the brake pedal is pressed, it closes the switch and turns on the rear brake lights. On construction and tactical equipment, you may find a pressure light switch. This type of switch uses either air or hydraulic pressure, depending on the equipment. It is mounted on the master cylinder of the hydraulic brake system or is attached to the brake valve on an air brake system. As the brakes are depressed, either air or hydraulic pressure builds on a diaphragm inside the switch. The diaphragm closes allowing electrical current to turn on the rear brake lights. EMERGENCY LIGHT SYSTEM The emergency light system, also termed hazard warning system, is designed to signal oncoming traffic that a vehicle has stopped, stalled, or has pulled up to the side of the road. The system consists of a switch, flasher unit, four turn signal lights, and related wiring. The switch is normally a push-pull switch and is mounted on the steering column. When the switch is closed, current flows through the emergency flasher. Like a turn signal flasher, the emergency flasher opens and closes the circuit to the lights. This causes all four turn signals to flash. Figure 2-71.—Brake light switches. 2-50