2008 Sierra HD dash lights

[BlueSierra2500HD]

The dash lights dimmer won't dim the lights any more. Also the lights are dim.
In addition the fog lights won't come on. Any ideas of the source of the problem?

 

[Parts007]

I had that problem in a Canyon, where the dash dimmer lights wouldn't dim, they were full high.

The problem was an open in the dimmer circuit, and the vehicle defaulted to full dash lights.

 

[vanhuntt]

As for the fog lights, you can replace them if they've given out, but i'd check wiring if there are problems with the connection. Also better if a trusted technician can take a look.