Automotive Online Electrical Tutorial: Covers basic electrical issues, alternators, relays and circuitry.Car Battery FAQ: Battery maintenance, myths, electrical testing, jump starting, failure and replacement are all discussed.HowStuffWorks: How Turn Signals Work: Photographs and animations describe the unusual device called a thermal flasher that makes your signals flash, and shows how turn signals cancel themselves after you've made your turn.OBD-II - On-Board Diagnostic System: Dedicated to helping the home and independent technician understand and use OBD-II technology through text, photos, and a discussion forum.Volvo Electrical Systems: Contains theory, troubleshooting and maintenance.