Fuse box Audi A4 (B5) - Fuses box diagram Fuse box in passenger compartment Audi A4 (B5). fuse box location. The unit is located under a cover at the end of the dashboard on the left-hand side. To open cover insert a screwdriver in the slot below the cover and pry it off. The crank handle for manual operation of the electric sun roof is clipped on the inside of the fuse box cover.