Mercury Grand Marquis owners have reported 1 problem related to fog light switch (under the exterior lighting category). The most recently reported issues are listed below. Also please check out the statistics and reliability analysis of Mercury Grand Marquis based on all problems reported for the Grand Marquis.
Vehicle headlights went out at highway speeds with no apparent warning. Pulled over and examined lights, only fog lights working. Turned off vehicle and restarted, lights worked. Sporadic lights working, then not working. Able to manually pull and hold dimmer switch to activate bright lights. After researching this problem on the internet I have discovered the problem is the same all across the country in the 2003-05 Mercury Grand Marquis. The lighting control module (lcm) is problematic and poses a safety concern for many owners. . Read more...
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