Chevrolet Trailblazer low beam headlights have dark shadow causing visibility issues and oncoming cars to flash high beams on Chevrolet Trailblazer

Some Chevrolet Trailblazer owners report experiencing visibility issues due to dark shadows from low beam headlights, which can result in oncoming cars flashing their high beams. Common problems include the low beam headlights suddenly turning off while the high beams remain functional. Swapping relays, particularly the HDM relay, has been noted to sometimes resolve the low beam issue. Additionally, troubleshooting steps such as checking fuses, replacing the dimmer and headlight switch, and ensuring the bulbs are in good condition are recommended. Disconnecting the DRL killer and trying different relays may also help diagnose the problem. In some cases, temporarily swapping the fan relay next to the HDM relay can fix the low beam issue until the faulty relay is replaced.