Preliminary Inspection
NOTE:
Many intermittent problems are due to poor electrical connections. Diagnosis of intermittent problems should begin with visual and physical check of all connections and wiring involved in the circuit before replacing any component of that particular system.
Verify customer complaint by operating suspected system. Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. 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 any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If no fault is found, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM .