Car Battery FAQ

Battery maintenance, myths, electrical testing, jump starting, failure and replacement are all discussed.
http://www.uuhome.de/william.darden/

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.
http://www.howstuffworks.com/turn-signal.htm

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.
http://www.obdii.com/

Automotive Online Electrical Tutorial

Covers basic electrical issues, alternators, relays and circuitry.
http://www.autoshop101.com/autoshop16.html

Volvo Electrical Systems

Contains theory, troubleshooting and maintenance.
http://www3.bc.sympatico.ca/Volvo_Books/elec2.html