Car had dimming of headlights, replaced alternator, replaced battery, checked ground. Problem has worsened, it is my son's car, he lives 500 miles away. He notes headlight dimming when brakes applied (ABS) . No warning lights on dash. He did have the new alternator tested to be sure it wasn't defective.
Any ideas of direction to go? Car has 90,000 miles, not worth putting much money into it. Still starts and runs for now.
Kevin