Electrical problem with radio, horn, cig. Lighter

Was this an aftermarket replacement lighter element that plugged into the original socket? If so, they have safeguards built in to prevent overheating if the element sticks in, and some elements short out that safety terminal resulting in a blown fuse. You overlooked a fuse or there's a burned-open fuse link wire under the hood. Those are in a bundle going around the left strut tower. To test them, you pull on them. If they act like a wire, they're good. If they act like a rubber band, they're blown.