Mercury Grand Marquis light failure with only high beam working on Mercury Grand Marquis

Some Mercury Grand Marquis owners report experiencing issues with their headlights, specifically that only the high beams are functioning. This problem may be due to a faulty dimmer switch that is bypassing the headlight switch, indicating a potential failure in the headlight switch itself. Additionally, a malfunctioning Light Control Module (LCM) located behind the glove box could require replacement to resolve the issue. In some cases, owners find that low beam bulbs need to be replaced if the high beams do not activate when pushing the multifunction/dimmer switch forward. Furthermore, checking the lighting module located under the dash, above the gas pedal, may reveal a simple fix for the problem. These issues can lead to low beam and permanent high beam lights not functioning properly, with only the high beam "flash" feature working intermittently.