I am having troubles getting my dash lights to work. I have replaced the "Dimmer Switch" in the dash, checked the lights in the gauge cluster and they are fine. The weird thing is that the only lights that dont work are the lights behind the Tach, Speedo, and the heater switches. All of my "other" lights, ie battery, high-beams, etc. work. Please help...cant see my gauges at night. NEED TO FIX ASAP! Any advice greatly appreciated.

it's most likley a fuse of some sort, either in your fuse panel or behind your glove box.

Jake - the post is over 2 months old. Odds are he's solved the problem by now or driven the truck off a cliff.

Hey guys, still havent fixed 'em. And am about ready to drive it off a cliff...

The dash lights and brake lights are wired through the same fuse. Check to see if your brake lights are working, if they aren't working then start with the fuse then check main power source to the fuse.
You will need the FSM electrical wiring schematics.
Good Luck

Brake lights are in fine working order, all fuses are good. Replaced bulbs, still not working...

Take a test light and follow the wiring back to the fuse.