I have a 1991 Cav. Z24 and the horn and dome light do not work. I replaced the fuse and it worked. Then it stopped working. Any suggestions... could it be a shorted or open wire somewhere?

Sounds like the fuse blew again and yes, that would mean you have a short somewhere.

I got the horn and dome light working. Now I need to ge the trunk light to work. There is a wire that goes to the light and one that goes to the plastic clip that hold the wires out of the way. The wire that goes to the clip has a metal thing inside of it.