Cavalier headlights flicker

The headlights on my 1990 Chevy Cavalier would flicker and then go out while driving. I replaced the headlight switch, and everything seemed fine. However, once I drove more than 20 miles at a time, the headlights started flickering. When I turned them off for a minute and then on again, the flickering did not return. The flicker did not seem to be related to rpm, and I didn’t notice any dash lights flickering. I am giving this car to my little sister as her first car soon, and I’d like to straighten up the issue ASAP. Thanks!!

Is it both headlamps or just one? I may well be a bad ground or a failing alternator. Good Luck. Looking at the voltage with a scope can tell you a lot in this kind of situation.

The headlight relay may be to blame. See what replacing it does.