Hazard Warning Lamps: Description and Operation

The turn signal switch is part of the multifunction switch on the steering column. The turn signal lamps and the hazard lamps are the same lamps, and they both utilize the turn/hazard lamp flasher. Turn signal voltage through the TURN/BU 20 A fuse 16 is only available when the ignition switch is in the START or RUN positions, and the turn signal circuit will only flash the bulbs on the selected side of the vehicle.

Turn signal lamp voltage is provided from the TURN/BU fuse to the normally closed contacts of the turn signal switch. The turn/hazard module supply voltage circuit connects the turn signal switch to the turn/hazard lamp flasher. The turn/hazard lamp flasher continuously opens and closes the circuit until the turn signal switch is moved to the OFF position. Current flows from the flasher through the turn signal flasher signal circuit back to the turn signal switch.
- When the turn signal switch is in the left turn position, the voltage is distributed by the left turn signal lamps supply voltage circuit to the left front park and turn signal lamps, the left rear park and the turn signal lamp, and to the left turn indicator bulb in the instrument cluster.
- When the turn signal is in the right turn position, the voltage is distributed by the right turn signal lamps supply voltage circuit to the turn signal in the right front park and turn signal lamps, the right rear park and turn signal lamp, and to the right turn indicator bulb in the instrument cluster.
- On vehicles with a single front turn signal bulb, an inline resistor is added to the circuit so that the bulb will draw the same current as in a dual front turn signal arrangement. The current flows through the resistor and is grounded through the opposite turn signal bulb, but sufficient voltage will be dropped through the resistor so that the opposite turn signal bulb will not illuminate.

The HAZARD 20 A fuse 5 supplies battery positive voltage at all times to the hazard switch. When the hazard warning switch is pressed, voltage is available to the turn/hazard lamp flasher through the hazard indicator supply voltage circuit. From the flasher, the turn signal flasher signal circuit returns voltage to the turn signal switch. Voltage is distributed on both the right turn signal lamps supply voltage circuit and the left turn signal lamps supply voltage circuit to the lamps and indicators. The hazard circuit will flash front and rear bulbs on both sides of the vehicle. The front turn signal lamps are grounded at G108 and G109. The rear turn signal lamps are grounded at G400 and G401.