electrical problem, headlights

My first suspect would be the dimmer switch itself. Is it a button on the floor that you push with your foot or is it a funtion of the blinker lever? The contacts in the switch is the first thing I would check. They are not blowing fuses, so you dont have a short to ground.

Turn them on , then check for power going into the highbeam switch to verify it is still there. Check to see if it is coming back out of the switch, if not its time to replace it. They have some pretty good diagrams at autozone.com now. Check them out for the wire colors in your car. All you should need is a cheap test light and some basic hand tools to find the problem.