GMC 2015 Sierra Owner's Manual page 411

10-48 Vehicle Care
Micro Usage
Relays
67 Fuel Pump 2
68 Air Conditioning
Control
69 Starter
Mini Relays Usage
70 Rear Window
Defogger
71 Engine Control
Module
Solid State Usage
Relay
72 Cooling Fan Clutch
Instrument Panel Fuse
Block (Left)
The left instrument panel fuse block
access door is on the driver side
edge of the instrument panel.
Pull off the cover to access the
fuse block.