I had another thought, I don't know about your 93, but my 96 has a daytime running light low output function. Any time the car is running the headlights are on, but in daytime in a dimmed mode. Is it possible you are seeing this mode on your headlights? To check, in daytime with the car running, watch the headlights and have someone manually block the photo sensor. If the lights get brighter there is nothing wrong.