F 250 2WD LD Pickup V8-5.4L SOHC VIN L (1997)
Interior Lighting Module: Flow of Diagnosis
1. The interior lighting system is a Generic Electronic Module (GEM) or Central Timer Module (CTM) controlled system.
2. Verify the customer concerns by operating the interior lamps.
3. Visually inspect for obvious signs of mechanical and electrical damage:
VISUAL INSPECTION CHART
MECHANICAL
^
Switch(es)
ELECTRICAL
^
Fuse(s)
^
Damaged wiring harness
^
Loose or corroded connector(s)
^
Circuitry
^
Damaged bulb(s)
4. If the concern is not visually evident, determine the symptom and proceed to the Symptom Chart. See: Symptom Related Diagnostic Procedures