electrical problems

Hello, Fellow Z-er's..... I have an electrical problem with my car. I purchased this a couple of months ago on E-bay, picked it up in Washington, DC area and drove it approximately 1200 miles , bringing it home. I parked it, and left it set for about a month. Then, when I got ready to title and tag it, and start doing some minor repairs, it wouldn't start. Not only would it not start, it has no exterior lights (headlights, tail lights, brake lights, and parking lights are not working) and the horn doesn't work, nor the electric windows.) The ignition won't engage the starter even though I've replaced the battery and made sure it was charged to max V/A. I am at a loss as to where to start looking in order to repair. Can you give me some hints? I think it may be in the ignition system ( that would explain the starter, but not the lights, horn, etc. What about the ECU? if I go into that, is there anything I should be aware of (such as CMOS transisters), or any other particular componet that would bear caution? Where I might obtain good information? Any one know of a sound plan of action for me to follow? I would be as appreciative. Regards, Richard

you might need a new altenator.