" electrical fiasco! "

Greetings, I am fortuneate owner an 01 tacoma xcab 3.4L 4x4. symptoms are as follows.. when my headlights are "ON" my cruise won't operate, when i apply the brakes with the lights "OFF" my dash lights up and the clock and stereo go dim. I've checked to see if the headlights and taillights and brake lights all work fine. Just curious to see if anyone else out there has had similar issues and could give me some direction. Any would be much appreciated, thanks!