They look like this. You can probably find this fuse holder in several places under hood. I suggested the cooling fan because that will have 10-12 gauge wire, and if you take the tome to unwrap the harness you can probably get enough wire to reach to both the blower relay, and the horn relay, eliminating the need for splicing wires. Blower motors can pull some serious current. A small amount of resistance from a poor connection will cause the wiring to get hot, leading to melted parts.