You need the actual electrical diagram for that year. Usually there are 3 manuals...service, electrical, and emissions. All complement each other, and leave a lot to be desired by themselves.
As to how much additional fuel it uses, wrong answer.
http://auto.howstuffworks.com/question424.htm Not authoritative of course, but pretty darn dumb IMO if we need to save gas to save money.
I'm sure I could put a dollar value on a life. DOT does it for every roadway project that is done. Pretty ridiculous IMO to say that we should spend all the money and resources for DRL (both in terms of what the automakers have to build/sell, plus fuel) if the cost benefit just isn't there. You can't legislate stupidity away, so don't try.
Per this articles figures
http://www.usatoday.com/money/autos/2003-10-28-lights_x.htm each life "saved" that I calculated was $28,000. It cost just over $1 billion dollars to save 37,000 lives, not including the fuel usage. Of course, GM would save money if everything was built exactly the same, mandating them in the US would mean the Canadian harnesses would be identical to ours.