I just bought a '75 280z for 800 well when I got it home the tailights, interior lights, driving lights and the blinkers all went out when I got home. I checked all the light bulbs and fuses and they all work. What should I check next.
Check your fuseable links, they must be tested w/ a continuity tester.(located near battery)
Check your relays, should be under the passenger side dash(doubt it's the relays though).
You might want to clean all connections also.
Check your fuse box for corrosion and your combo switch for wear and corrosion. Did you check the fuse for continuity (out of the fuse box), or did you just do a visual check? When I had the corrosion problem, the fuse would heat up slowly, so it wouldn't blow. Instead, the solder would melt and lose continuity.