THAE CAR IS AN 84 TRANS AM L69 5 SPD

So far (That I know) My Horn, Radio, Cigarette lighter, and dome light, Have given up the ghost......Fukk!!!.....any ideas of where to start to remedy this problem......And YES all fuses are good, I pulled them ALL and visually checked......and everything else works in the car....gauges, flashers, turn signals, hvac/heat controls.......... but not having a horn sucks..... for the time being I just ran a hot wire straight from the battery to get my tunes back......But I dont like the Idea of it being like that for long...Fuses prevent fires, and Fire prevention is good.....so I dont want to BuBBa up a horn or interior light setup unless I run it thru the fuse panel in an open slot, but thats a last resort!!!!!....Are these afore mentioned items even on the same fuse/ circuit or ground? If I did run a circuit for these Items thru an open spot in the fues panel, could I run them all on the same cicuit, as in all on one fuse? If so what rating?

EDIT - Well I dug out the continuity tester and.....Im pretty sure that all the things that died are on the same fuse.....Soooo Where is the ground for the above mentioned items?

DANGGIT!! I meant to post this in the electronics board.....any Mod Wanna move it? See what happens when you have several windows open a once.......