wiring 1978 corolla

Hi. My 1978 Corolla sr5 liftback suddenly had many problems. Components failed, such as tach, radio, dash lights, horn, oil press. gauge, temp gauge, and probably others. I cleaned under dash fuses, checked fusible link and under hood fuses, cleaned battery ground at block, cleaned motor ground at firewall. Haven't been able to find any more ground points . Still no results and am out of ideas. Battery is one year old and fully charged. Any help! Ron