Troubleshooting Hints

Perform before beginning System Diagnosis
1. Always suspect an open lamp filament before proceeding with diagnostics.
2. Make sure Lamp Connectors are free from corrosion.
3. Check that grounds G200, G106 and G105 are clean and tight.
4. Check Fusible Link Z for open.
5. Check TAIL LTS Fuse 10 and I/P Dimmer Fuse 13 for open. If fuse(s) are open, refer to Chart #15 in this section. Chart #15 Fuse(S) Blows When Replaced
6. On Pontiac Models if Headlamp door(s) do not open and Headlamps do not illuminate, repair Headlamp door(s) failure first. See "Headlight Doors," refer Headlamp Door. Headlamp Cover
^ Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove "GOOD" in a continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should he checked by monitoring for a voltage drop with the system operational (under load).
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems (Refer to "Diagnostic Aids/General Troubleshooting Procedures,"). Diagnostic Aids
^ Refer to System Diagnosis. System Diagnosis