Had a similar problem with my 85 camaro, horn and interior lights didn't work and radio wouldn't save presets. Do your interior lights come on? Mine didn't, checked fuses and found blown fuse. Replaced and after about 1/2 hour blown fuse again. Ended up being the cigarette lighter had a short. Disconnected it and no problems then replaced with new one and everythings working fine. Hope this helps. Pete
67 red camaro convertible, 78 silver anniversary vette, 1976 kz900, 1985 Z28 camaro, 1971 chevelle. Too many toys now My four car garage is no longer big enough.