2018 GMC Sierra K2XX Fuse Box Diagram

The fuse block is in the engine compartment on the driver's side, forward of the strut tower and behind the headlamp; the lid comes off once the catches are pressed in. A second, smaller cover underneath keeps the relays in place.

The MY2018 tray is laid out exactly as the 2017 one - cartridges 3 to 13 along the top, micro blades through the centre, relays filling the lower half, links 72 and 73 at the top right, running boards on 74 and fuel pump prime on 76. Relay 71 now switches the vacuum pump as well as the cooling fan clutch. The cabin pump and vacuum pump fuses the handbook lists as 77 and 79 have no socket on this plate.

You reach this block from the driver's seat: open the door and lift the cover off the end of the dashboard. The block is the one that holds the truck's fuse puller.

The MY2018 assignment is the MY2017 assignment with one wording change - the garage door opener fuse 3 is listed as the universal remote system. The sockets run in bands from the single fuse 1 at the top left down to the heated-seat fuses 43, 44 and 45 at the bottom, with the retained accessory power relay 49 boxed around the cigarette lighter fuse 12 halfway down the left-hand side.

The passenger end of the dashboard carries this block behind a removable cover, opposite the driver's-side block that holds the fuse puller.

One position changes for MY2018: 37, a spare on earlier trucks, is listed as the battery system fuse. The rest of the plate is unchanged - accessory outlets 1 and 2 stacked in the top left corner, the three relays down the left edge, the tall fuses 23, 26 and 27 across the middle, and the front blower cartridge 43 with the passenger seat fuse 47 at the bottom.