click here to learn a E36 M3-ton about automotive electrical systems
at times a little preachy, but IMO the education is worth enduring the preaching. hey, he's also selling the stuff he's writing about, so the preaching is to be expected. there's a ton of info here, and he does a decent job of breaking it down for the inexperienced reader, as well as keeping a lot of tech in some places for a more seasoned veteran.