FOG LAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS ARE DIM
WITH ENGINE IDLING OR
IGNITION TURNED OFF.
1. Loose or corroded battery cables. 1. Clean and secure battery cable clamps
and posts.
2. Loose or worn generator drive
belt.
2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system, refer
to Group 8A, Battery.
4. Battery has insufficient charge. 4. Test battery state-of-charge, refer to
Group 8A, Battery.
5. Battery is sulfated or shorted. 5. Load test battery, refer to Group 8A,
Battery.
6. Poor lighting circuit Z1 ground. 6. Test for voltage drop across Z1 ground
locations, refer to Group 8W, Wiring
Diagrams.
7. Both fog lamps are defective. 7. Replace both fog lamp bulbs.
FOG LAMP BULBS BURN
OUT FREQUENTLY
1. Charging system output too high. 1. Test and repair charging system, refer
to Group 8A, Battery.
2. Loose or corroded terminals or
splices in circuit.
2. Inspect and repair all connectors and
splices, refer to Group 8W, Wiring
Diagrams.
FOG LAMPS ARE DIM
WITH ENGINE RUNNING
ABOVE IDLE
1. Charging system output too low. 1. Test and repair charging system, refer
to Group 8A, Battery.
2. Poor lighting circuit Z1 ground. 2. Test for voltage drop across Z1 ground
locations, refer to Group 8W, Wiring
Diagrams.
3. High resistance in fog lamp circuit. 3. Test amperage draw of fog lamp circuit.
4. Both fog lamp bulbs defective. 4. Replace both fog lamp bulbs.
FOG LAMPS FLASH
RANDOMLY
1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across Z1-ground
locations, refer to Group 8W, Wiring
Diagrams.
2. High resistance in fog lamp circuit. 2. Test amperage draw of fog lamp circuit.
3. Faulty fog lamp switch. 3. Replace headlamp switch.
4. Loose or corroded terminals or
splices in circuit.
4. Inspect and repair all connectors and
splices, refer to Group 8W, Wiring
Diagrams.
5. Bad connection between
headlamp switch and BCM
5. Test and diagnose circuit between
headlamp switch and BCM.
6. Loose relay. 6. Inspect and reset fog lamp relay.
7. Faulty Body Control Module. 7. Replace Body Control Module.
8L - 6 LAMPS LH
DIAGNOSIS AND TESTING (Continued)
To Next Page
Loading...
