Kayva

Hey everyone, I am at my wits end. I have a 1977 280Z with an automatic. The car sat for a little while and now I cant get it started. Here is a list of what is going on: With key in ACC I get fasten seat belt light, buzzer, and voltage light, when key is advanced to ON, I get a click from passenger side and from engine bay passenger side then everything goes out. No gauges work except fuel gauge No interior lights work. Headlights do work, but no tail lights, turn signal lights, or brake lights. Radio does not work I have replaced the alternator, voltage regulator, the ignition switch, the ignition relay, fusible links (will upgrade to powerblock soon), done the starter relay mod, had the battery checked, and now want to cry myself to sleep. I have searched and tried multiple ideas. Kind of wondering if the seat belt interlock could be an issue, but am not sure on how to bypass it. Thanks any and all suggestions would be greatly appreciated, I want to drive my car this summer.