Troubleshooting Hints - Exterior Lights

PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS
1. Check Underhood Bussed Electrical Center (BEC) SBM/LCM Fuse 2, HDLP Fuse 40, LP PK Fuse 24, HZDT/SG Fuse 25, T/SIG Fuse 3, and STOP Fuse 20 by visual inspection.
2. Check I/P BEC LP PK L Fuse and LP PK R Fuse by visual inspection.
3. If a turn indicator does not light, but turn signals work, check bulb, connections, and wiring to indicator.
4. If the turn lamps stay on (do not flash) during the hazard function and both turn signal functions, replace the turn signal/hazard flasher module.
5. If only one light does not operate, check bulb, socket, and related wiring (see schematic).
6. If a group of lights are inoperative, check common power and ground wiring (see schematic) to those bulbs. Also, check for proper terminal contact at the BEC and in-line connectors.
7. Check that grounds G105, G106, G202, G400, and G402 are clean and tight.
8. If the LH cornering lamp is inoperative during the LH turn signal function, but the turn lamps operate:
^ Check for an open or short to ground in CKT 57 (ORN) between the LH cornering lamp and S200.
^ Check for an open in CKT 150 (BLK) between the LH cornering lamp and S110.
^ If all OK, replace the LH cornering lamp.
9. If the RH cornering lamp is inoperative during the RH turn signal function, but the turn lamps operate:
^ Check for an open or short to ground in CKT 58 (BLK) between the RH cornering lamp and S201.
^ Check for an open in CKT 250 (BLK) between the RH cornering lamp and S109.
^ If all OK, replace the RH cornering lamp.
10. Before component replacement, check for poor connections at related component and in-line harness connector terminal connections.
^ 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) (refer to General Troubleshooting Procedures).
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems (refer to General Troubleshooting Procedures). Diagnostic Aids