You need to be more definitive. It sounds like it is in your remote settings at the switch, or a loose connection.
headlight relay location on a 2004 mercury grand marquis
According to the 2004 Mercury Grand Marquis Owner Guide : ( 19.0 US. gallons )
2004 mercury grand marquis fan stop working
They are tied to either the brake lights or the tail lights.
On a 2004 Mercury Grand Marquis : firewall 4 - 8 3 - 7 2 - 6 1 - 5 front of vehicle
According to the 2004 Mercury Grand Marquis Owner Guide : With engine oil filter change : ( 6.0 U.S. quarts of 5W-20 )
According to the 2004 Mercury Grand Marquis Owner Guide : ( " regular " unleaded gasoline , 87 octane )
The cabin air filter, in your 2004 Mercury grand Marquis, is located behind the dashboard on the passenger side. The air filter is directly behind the glove compartment.
According to the 2004 Mercury Grand Marquis Owner Guide : With engine oil filter change : ( 6 quarts )
YES. The harness is behind the bumper in proximity of the location of the lights.
YES. The harness is behind the bumper in proximity of the location of the lights.
Take it to a repair shop.