Preliminary Inspection

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2006 BMW M3, 2005 BMW M3, 2004 BMW M3, 2003 BMW M3, and 2002 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.

Verify customer complaint by operating system. Visually inspect for obvious signs of mechanical and electrical damage. Check generator belt tension and condition. Ensure that battery voltage is within specifications. Inspect for blown fuses and damaged relays. For fuse and/or relay identification, see WIRING DIAGRAMS .

Verify ground connection integrity between engine, body, battery and generator. Check for 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, check for conditions that might cause an intermittent situation.