GMC Sierra (2008) - fuse box diagram - Auto Genius Dec 28, 2016GMC Sierra (2008) – fuse box diagram Year of production: 2008 Instrument Panel Fuse Block The instrument panel fuse block access door is located on GMC Sierra Denali - 2008 Fuse Box Diagram GMC; Sierra Denali - 2008 Fuse Box; If a locked door is opened without using the RKE. transmitter, a ten second pre-alarm will occur. The horn. will chirp and the lights will flash. If the key is not. placed in the ignition and turned to START or the door. is not unlocked by pressing the unlock button on the.