Dear Car Talk;
What causes headlights to pulse? I have noticed when driving that both the low and high beams (more noticiable on the highs) will randomly pulse. They will quickly go a little brigher and/or a little dimmer. KInd of like a flicker, but the lights never go out. SInce it’s affecting all of hte lights, I hesitate to think it’s stickly a bulb issue. The interval does not seem to have a pattern and it doesn’t seem related to hitting bumps in the road.
Car just had its 50000 checkup, so I wouldn’t suspect the alternator or battery would the culprit. We also just had the CCM replaced by a VW Dealership for an unrelated problem.