Couple things.
The factory fog light switch is below the dome light switch below the light switch,
That blank panel , to the left of the radio, is the panel for the rear wiper and hatch release. We have the same wiring harness as all the utilities (Blazers).
On the pickup wiring harness the airbag disconnect switch/wiring is there.
Can you use the wiring? YES! I even used the switch
(I've added a couple indicator LEDs since this picture)
Heres the wiring:
Pin A YEL = Accesory Voltage
Pin B DK GRN = Rear Window washer Control
Pin C GRY = Rear Window Wiper Switch Signal
Pin D BLK = Trunk Release Switch Signal
Pin E BLK = Ground
Pin F GRY Instrument Panel Lamp Fuse Supply Voltage