Troubleshooting Hints - Interior Lights

PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS
1. Check the RH rear junction block INT LP Fuse by visual inspection. If open, check for a short to ground in CKT 640 (ORN).
2. Check the RH rear junction block PWR DR LK Fuse by visual inspection. If open, check for a short to ground in CKT 1540 (ORN).
3. Check the IP fuse block IGN I Fuse (Oldsmobile) or CHIME Fuse (Buick) by visual inspection. If open, check for a short to ground in CKT 39 (PNK).
4. If the auxiliary power outlet is inoperative, check the IP fuse block AUX PWR Fuse by visual inspection. If open, check for a short to ground in CKT 1241 (BRN).
5. If all cigar lighters are inoperative, check the IP fuse block C/LTR Fuse by visual inspection. If open, check for a short to ground in CKT 1040 (ORN) (Oldsmobile) or CKT 1640 (ORN) (Buick).
6. If only one interior lamp does not operate, check the bulb, the connections, and the related wiring (see schematic).
7. Check that grounds G103, G201, G202 and G302 are clean and tight.
8. Before component replacement, check for poor connections at related component and in-line harness connector cavity connections.
9. Check for broken (or partially broken) wire inside the insulation which could cause a 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).
10. Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.