wiring problem

[tavius]

I can not turn on my headlights without my ac display going off, nor do my brake lights work .
I have check all the fuses and replaced the headlight switch, but i still can't get my headlights, ac control display, and brake lights to work at the same time. The other day i just got in the truck and this problem occured. What could be causing this? Has anyone else had this problem?

[More Power]

What year vehicle is it? Has there been any electrical mods performed?

MP