2004 GMC Seira 4×4 6.0 Under Hood Fuse Box Diagram 2004 GMC Seira 4×4 6.0 Under Hood Fuse Box Diagram 2004 GMC Seira 4×4 6.0 Under Hood Fuse Box Map Fuse Panel Layout Diagram Parts: UBEC bracket, engine harness, under hood bussed electrical center.