Preliminary Inspection

Verify customer complaint by operating suspected system. Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. For fuse and/or relay identification, see FUSES & CIRCUIT BREAKERS article in ELECTRICAL.

Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. Check for a broken or partially broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If no fault is found, perform self-diagnostics. See iSELF-DIAGNOSTIC SYSTEM .