Troubleshooting Hints - Interior Lights

1. Check the condition of the CIG LTR FUSE 13, CTSY FUSE 3, HORN MINI FUSE and the PARK LPS FUSE 9. If any fuse(s) is open, then LOCATE and REPAIR source of overload and REPLACE fuse(s).
2. Check that grounds G105, G200, G400 (Suburban, Utility and Crew Cab), and G404/G405 (Suburban W/Auxiliary Lighting) are clean and tight.
3. Check for open filaments in inoperative lamps. If I/P Compartment Box Lamp remains ON with the Switch OFF, then REPLACE the lip Compartment Box Lamp Assembly. If Underhood Reel Lamp remains ON with the Switch OFF, then REPLACE the Underhood Reel Lamp Assembly.
- 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 be 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 "Troubleshooting Procedures"). Diagnostic Aids