Re: Get yourself a good digital multimeter and code tester; a Chilton's or Haynes resource would help too !
The problem with Chilton is that they give you great picture and diagram of parts, but they don't show you where that part is on the car.
It took me an hour to trace the fuel lines and find the fuel filter because they didn't show where it was located.
Same with the AC low end to rechage (with the new stuff, of course).