Test U: Lights On, Chime Inoperative

Inspect PARK LAMPS fuse (15-amp) in engine wiring harness junction block No. 2. If PARK LAMPS fuse is not open, go to next step. If PARK LAMPS fuse is open, go to step 3 .
Turn ignition switch to LOCK position. Disconnect multifunction alarm module 8-pin harness connector. Using test light connected to ground, probe seat belt, ignition key, lights alarm harness connector terminal A1 (Gray/Black wire). Turn headlight switch to parking lights or headlights ON position while observing test light. If test light illuminates, go to step 5 . If test light does not illuminate, go to step 6 .
Replace PARK LAMPS fuse. Turn headlight switch to parking lights or headlights ON position. If fuse opens again, go to next step. If fuse does not open again, go to step 7 .
Repair short to ground in Gray/Black wire between headlight switch and multifunction alarm module or between multifunction alarm module and radio. After repairs, go to step 7 .
Check multifunction alarm module harness connector for poor connection. If multifunction alarm module harness connector is okay, replace multifunction alarm module. See MULTIFUNCTION ALARM MODULE under REMOVAL & INSTALLATION. After repairs, go to step 7 .
Using test light connected to ground, probe headlights switch terminal "I" (Gray/Black wire). See Fig 1 . Turn headlight switch to parking lights or headlights ON position. If test light illuminates, go to step 8 . If test light does not illuminate, go to step 9 .
Turn ignition switch to LOCK position. Reconnect all connectors and reinstall components that were removed. Perform audible warnings system check. See AUDIBLE WARNINGS SYSTEM CHECK under TROUBLE SHOOTING.
Repair open in Gray/Black wire between headlight switch and multifunction alarm module. After repairs, go to step 7 .
Replace headlight switch. After repairs, go to step 7 .

Fig 1: Identifying Headlight Switch Harness Connector Terminals

Courtesy of GENERAL MOTORS CORP.