1997 Gmc Sierra Tail Lights Dash

Have you checked applicable fuses? Not only check that fuse hasnt blown, but also check for voltage on the fuse circuit. You may need to check the headlamp switch.

The park lamp fuse carries voltage to headlamp switch for tail lamps. When the headlamp switch is turned on, the brown wire carries voltage to tali lamps. The brown wire for tail lamps is black, check voltage and ground.

I meant to say the ground wire for tail lamps is black.