For 1990-2009 cars

Symptom | Procedure
--- | ---
Both fog lamps are inoperative. | Chart 1.
The left fog lamp is inoperative. | Check the bulb. If OK, disconnect the left fog lamp connector, BLK 2-way. Turn the fog lamps ON. Connect a test lamp between circuit 34 and ground. If the test lamp bulb lights, open circuit 150. If the test lamp bulb does not light, open circuit 34.
The right fog lamp is inoperative. | Check the bulb. If OK, disconnect the right fog lamp connector, BLK 2-way. Turn the fog lamps ON. Connect a test lamp between circuit 34 and ground. If the test lamp bulb lights, open circuit 150. If the test lamp bulb does not light, open circuit 34.
The fog lamps and fog lamp switch illumination is inoperative. | Open circuit 350 or faulty fog lamp switch
The fog lamp switch illumination is inoperative and the fog lamps operate normally. | Faulty fog lamp switch
The fog lamps do not turn OFF with the high beam headlights ON. | Disconnect the I/P switch connector, NAT 4-way. Connect a test lamp between circuit 1200 and ground. If the test lamp is ON, there is faulty fog lamp switch. If the test lamp is OFF, open circuit 1200 between the UHFB and I/P switch.