Cadillac STS - 2006 Fuse Box Diagram diagramfusebox›CadillacCadillac; STS - 2006 Fuse Box; If the alarm does not sound when it should, check to. see if the horn works. The horn fuse may be blown. To. replace the fuse, see. Fuses and Circuit Breakers on. page 5-105. If the fuse does not need to be replaced, you. may need to have your vehicle serviced. Cadillac STS (2005 - 2006) - fuse box diagram - Auto Genius Cadillac STS (2005 – 2006) – fuse box diagram. Year of production: 2005, 2006. Underhood Fuse Block. The underhood fuse block is located in the front of the engine compartment on the passenger’s side of the vehicle.