headlights

I have had my '92 crown vic for about a week. I bought it used, but it is in good condition. I don't have the money to buy a book on the car yet and i am having a problem with my headlights. they were working fine until last night. I had my brights on and then they started to flicker. i turned them to low and they started going out, then i would hear a grinding type sound and they would come back on. That happened for about two miles and then i got home. Does anyone have an idea as to how i can fix the problem or what it might be? I would greatly appriciate it.
thanks,

befuddled

Check the multifunction switch(turn signal)