Where the door lock fuseon99 grand Marquis - 1999 Mercury Grand Marquis

SOURCE: remove front door panel on 1995 merc grand marquis

http://www.autoclinix.com/Mercury/Front%20Speakers2.htm

SOURCE: door locks 2003 grand marquis ls stopped working

check fuse

SOURCE: i have a 1991 grand marquis my licsence plate

Check the fuses.

SOURCE: my door lock remote will not function and new

have you tried to press/hold lock button for 30 secs.
the code changes everytime you use the remote so that only your remote unlocks your car,not everybody elses.the key has a code inbuilt into it so the car will only start with your key...(this is dealer programmable)

SOURCE: 2008 grand marquis door locks just stopped working

Hello fellow Grand Marquis owner...

Fuses 2 and 9 in the central junction box protect this system.

There is a thing called the 'Driver Door Module' (DDM) that controls both the things that you are having trouble with.

If you want to test this module, a voltmeter will be necessary. The wiring diagram is available from Chilton either in a manual (which you should be able to borrow from a library), or online (if your library has the ChiltonLibrary available to you... you'll need a library card).

On the module, check for +12 volts on pins 10, 11, and 22. Check for ground on pins 23 and 24.

Working with the diagram is definitely the way to go.

Good luck from Detroit, MI.