Troubleshooting Hints - Exterior Lights

PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS
1. Check I/P Fuse Block SIG/BU/LPS BTSI/COR Fuse 1B, BRK/HZRD LPS Fuse 6B, PARK LPS/INT LPS Fuse 6C, and PERIMETER LT Fuse 8A, and LCM/HDLP Circuit Breaker by visual inspection.
2. If one of the the Indicators goes on when the Park Lamps are turned on, check Front Park/turn Lamp on that side.
3. If Turn Lamps stay on (do not flash) in both left turn and right turn, replace Turn Flasher.
4. If Hazard Lamps stay on (do not flash) in HAZARD, replace Hazard Flasher.
5. If a Turn Indicator does not light, but turn signals work, check bulb, connections, and wiring to indicator.
6. If only one light does not operate, check bulb, socket, and related wiring (see schematic).
7. If Stoplamps do not turn off, adjust or replace Cruise/Shift Interlock/Brake Switch as necessary.
8. Check that grounds G104, G105, G201, G202 and G402 are clean and tight.
9. If any monitored exterior lamp is inoperative, but the Adaptive Lamp Monitor (if equipped) does not indicate the outage, then refer to Lamp Monitor for diagnosis. Lamp Out Indicator
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).
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.