Help...No Power

Could use a little advise. I got this '74 Duster from a family member that needed money.
Its got slant six electronic ignition. I towed it back to my house. He had put new battery and various other new parts on the car. Anyhow, Battery has a full charge I put my gauge on it.
But has no power anywhere no headlights interior lights etc.... Checked the fusible link appears good. I know it has to be a bad ground or something loose? Reason why I think loose wire or bad ground is because when I go to crank the car it gives off (usually) one click and that's it. Then dead. Any ideas. Ill add a couple pictures of fusible link and bulk head.
Thanks, Larry.

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