I have a 1978 280z and all of a sudden the passenger headlight is dim and the tail lights and instrument panel lights do not work I have checked the fuse box replaced the bulbs in the tail lights and they still are not working. any clues?

Ug, electrics.

The first things to check are the areas of wire that have a greater exposure to the elements. Check connectors for corrosion. Check grounds for clean contacts. After that, I think someone who has in general better luck with sorting these types of issues than I do had better chime in.

I would double check the fuses. Sometimes they can detach inside and they'll look good but not make a connection. The early Z's had one fuse for each headlight and if one blew, that headlight would be dim.

Ttiger identified the EXACT problem that I had, for which I spent a pathetic number of hours tracking down. Turns out that the fuse wasn't blown, just so dirty that it lost its continuity (I replaced it, in fact, I was so upset that I didn't see such a simple item that I also replaced all the other fuses... just because I could).