Preliminary Inspection

Verify customer complaint by operating system. Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses. For fuse and/or relay identification, refer to illustrations. See Fig 1 and Fig 2 . Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. Check system grounds. Check for missing or damaged connector seals. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Pay special attention to harness routing where wires are hinged or make sharp bends. Ensure any aftermarket electronic equipment is properly installed. Before performing tests, check for proper operation of automatic door locks. If door locks do not operate properly, repair power door lock system as necessary. See DOORS . Check for proper operation of RKE system. If RKE system does not operate properly, repair RKE system as necessary. See REMOTE KEYLESS ENTRY SYSTEMS article under ACCESSORIES AND BODY, CAB. Check for proper operation of horn. If horn does not operate properly, repair horn system as necessary. See STEERING COLUMN SWITCHES article under ACCESSORIES AND BODY, CAB. Check for proper operation of headlights. If headlights do not operate properly, repair headlights as necessary. See HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article under ACCESSORIES AND BODY, CAB. If fault is found, repair as necessary. If no fault is found, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM.

Fig 1: Identifying Instrument Panel Fuse Block Fuses

Courtesy of GENERAL MOTORS CORP.