One problem related to battery has been reported for the 2004 Mercury Grand Marquis. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Mercury Grand Marquis based on all problems reported for the 2004 Grand Marquis.
My mother-in-law has a 2004 Grand Marquis & last night when she started the car to go home after visiting us, the headlights would not come on at all. . . . Additionally, the interior lights have come on all by themselves intermittently, and consequently, the battery is drained each time it happens. The interior problem may or may not fix itself by starting/shutting off/opening/closing door. All I did was type "2004 Mercury Grand Marquis" in yahoo search & a multitude of similar problems came up in the results: all stating a defective light control module (lcm). I am going to take the one out of her car today & take it apart & inspect it for cracked ("cold solder") solder joints as almost anything with a pc board ( (made in the last 25 years especially) tends to develop cracked solder because they are made cheaply by using as little solder possible to hold the joint together (when new, anyways) . Yet another cheap, modern junk electronic item pumped out in bulk by the thousands that the manufacturer will not support, unless it fails within the warranty period! I cannot believe Ford motor company won't issue a recall for this problem as it is not an isolated problem, according to my research! maybe once someone dies in a car wreck from the lights going out while they're going down a freeway @ 70mph, someone will get a good lawyer and sue the pants off of Ford motor company!! class action lawsuit, anybody?.