Unfortunately wiring problems are hard to troublehsoot over the internet. :p
The best advice I can offer though 1. make sure you checked all the fuses. I had an Escort that the radio woudln't work in. Replaced the radio fuse and it stil wouldnt do anything checked the wiring, ran a bunch of short tests on the radio itself, (it wasnt radio it was a cd player but radio is quicker) come to find out the fuse for the interior lights was also connected to the radio circuit and it was blown. Replaced it and it worked fine. So check all of them even if you think they arent related.
2. If you have a multimeter (or know someone who does) an a wiring diagram of the lights, check to make sure the dimmer switch is getting power first from the light switch, then check to see if the dash light circuit is getting power from the dimmer switch. This may be something as simple as a loose ground wire, but it think its more likely that the dimmer switch has gone bad. ($hit happens)