You've more than one problem unless there's a common dash harness connector.
One sure fire way to diagnose the dimmer is to see if the CC's temp display goes out when the lights are turned on... I can't rememer if the clock goes dark too... might. You can also bypass the dimmer by jumpering the white wire with green stripe and the white wire with black stripe. If it is the dimmer, you'll still find voltage as the dimmer controls the ground side of the equation, not the positive.
Do your dome lights work? Manually turned on and when the door is opened? Have your fog lights been rewired to operate when the headlights are not on? If so their relay is probably getting its signal from the taillight circuit or the gauge lighting circuit. Diagnose the gauge and then test the taillight relay, taillight failure module and fuse (actually, just replace the fuse, it may be bad and you just don't see the fracture).
I'll look up the wiring diagrams later and see if anything else comes to mind... just got home from work and need to chill for a while.
