Hey peeps I drive a 97 hatchback and have a problem. I cant seem to figure out what the problem is. When I am driving at night my lights seem to dim all of a sudden and then go back to normal. it isn't too noticeable, but it irritates the heck out of me. I notice that when i tend to be on a higher rpm the lights brighten up when I am driving normally it dims and lightens over now and then my gauge also seems to correspond with my headlights.

PLEASE HELP!! THANKS!