Preliminary Inspection
Verify customer complaint by operating suspect system. Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses. See Fig 1. Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. 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. Ensure ground connections are clean and tight. Check for proper installation of any aftermarket electronic equipment that may affect integrity of other systems. If problem is found, repair as necessary. If problem is not found, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM .