Fog/Driving Lamp: Description and Operation

CIRCUIT OPERATION
The fog lamps are controlled by the fog lamp switch and fog lamp relays. The fog lamps operate only when the headlamp switch is in the PARK or ON position, and the operator has selected low-beam operation. When the headlamps are in high-beam operation, the fog lamps will not operate.

Power for fog lamp relay #1 is supplied on circuit L7. This circuit is HOT when the headlamp switch is in the PARK or ON position only and connects to the normally CLOSED contacts of the relay.

Circuit L139 connects from the contact side of the relay #1 to the coil side of relay #2. When the operator turns the fog lamps ON a ground path is completed on circuit L35 through the fog lamp switch to circuit Z3. This causes the contacts in relay #2 to CLOSE connecting circuits L38 and L39.

Circuit L38 is the feed for the relay and protected by a 15 amp fuse located in cavity A of the Power Distribution Center (PDC). Circuit L39 connects from the relay to the lamps. Ground for the lamps is supplied on circuit Z1

If the high beam lamps are on, circuit G34 energizes the fog lamp #1 relay When the relay energizes, the contacts OPEN and power is not supplied to the fog lamps. Circuit Z1 provides ground for the coil side of the fog lamp #1 relay.