There are conflicting wire lists so you will need to verify the right one.
MODEL YEAR(S)
GRAND MARQUIS 2003 -2004
KEY T-HARNESS IMMOBILIZER
FDKEY-6 N/A FORD'S TRANSPONDER ANTI-THEFT SYSTEM, See NOTE #1
PART COLOR LOCATION
12 VOLT CONSTANT BROWN (+) and LIGHT GREEN (+) @ IGNITION SWITCH HARNESS
STARTER RED / LIGHT BLUE (+) @ IGNITION SWITCH HARNESS
STARTER 2 N/A
IGNITION 1 WHITE/ YELLOW (+) @ IGNITION SWITCH HARNESS
IGNITION 2 PINK/BLACK (+) @ IGNITION SWITCH HARNESS
IGNITION 3 N/A
ACCESSORY /HEATER BLOWER 1 GRAY / YELLOW (+) @ IGNITION SWITCH HARNESS
ACCESSORY /HEATER BLOWER 2 BLACK/ GREEN (+) @ IGNITION SWITCH HARNESS
KEYSENSE N/A
PARKING LIGHTS ( - ) WHITE/ BLACK (-) @ LCM, GREY 16 PIN Plug, Pin 13, See NOTE #2
PARKING LIGHTS ( + ) BROWN (+) @ LCM, BLACK Plug, Pin 4, See NOTE #2
POWER LOCK PINK / YELLOW (TYPE C), See NOTE #3 IN DRIVERS DOOR HARNESS
POWER UNLOCK PINK/LIGHT GREEN (TYPE C), See NOTE #3 IN DRIVERS DOOR HARNESS
DOOR TRIGGER DARK BLUE (-) and BLACK/ ORANGE (-) Use both, See NOTE #5 @ LCM Module, See NOTE #2
DOMELIGHT SUPERVISION DARK BLUE (-) (Requires #775 relay) @ LCM Module, See NOTE #2
TRUNK RELEASE PURPLE / YELLOW, See NOTE #4 IN DRIVERS DOOR HARNESS
SLIDING POWER DOOR N/A
HORN DARK BLUE (-) @ STEERING COLUMN HARNESS
TACH Any wire that is NOT RED or RED / LIGHT GREEN (AC) @ IGNITION COIL or FUEL INJECTOR
WAIT TO START LIGHT N/A
BRAKE LIGHT GREEN (+) @ SWITCH ABOVE BRAKE PEDAL
FACTORY ALARM DISARM N/A
ANTI-THEFT FORD'S TRANSPONDER ANTI-THEFT SYSTEM, See NOTE #1 @ IGNITION SWITCH TUMBLER
EXTRA INFORMATION
NOTE #1: This vehicle is equipped with a Special Anti-theft key, to remote start you will need a Bypass module 791, use this module IF you have a extra ignition key to place inside the 791 to remote start, if you do not have an extra key to use or wish not to have a key placed inside this bypass module, we OFFER a KEYLESS INTERFACE BYPASS MODULE that does not require a key to be placed inside the bypass module, this is Part # PKALL or PKFM, either one will work, to order, go to the INTERFACE BYPASS MODULE PAGE on this website. NOTE #2; the LCM (Lighting Control Module) is located to the right of the steering column. You can get to the harness of the LCM between the steering column and the LCM Module. NOTE #3: If vehicle is equipped with a FACTORY KEYLESS ENTRY System, then the vehicle has a TYPE B Door Locking System, vehicles without FACTORY KEYLESS ENTRY, have a TYPE C Door Locking System. Vehicles with the KEY PAD on the Door are considered to have KEYLESS ENTRY. NOTE #4: this vehicle uses a 5-wire TRUNK Release System that requires an extra relay part #775, to connect, See DIAGRAM NOTE #5: when connecting to an ALARM SYSTEM, use both DOOR TRIGGER wires and DIODE ISOLATE, to connect, See DIAGRAM
#500061: 2004 MERCURY GRAND MARQUIS 4DR SEDAN
Security
WIRE COLOR POLARITY LOCATION
Battery LT. GREEN/ VIOLET AND YELLOW (+) AT IGNITION SWITCH HARNESS
Ignition 1 WHITE/ YELLOW (+) AT IGNITION SWITCH HARNESS
Starter 1 RED / BLUE (+) AT IGNITION SWITCH HARNESS
All Door Trigger BLACK/ BLUE (+) AT UNDERDASH LIGHT
THIS WIRE MAY ALSO BE FOUND IN DRIVER'S KICK PANEL.
Domelight Super BLACK/ BLUE (+) AT UNDERDASH LIGHT
THIS WIRE MAY ALSO BE FOUND IN DRIVER'S KICK PANEL.
LF Latch BLUE (-) AT MODULE TO RIGHT OF STEERING COLUMN
RF Latch BLACK/ ORANGE (-) AT MODULE TO RIGHT OF STEERING COLUMN
LR Latch BLACK/ ORANGE (-) AT MODULE TO RIGHT OF STEERING COLUMN
RR Latch BLACK/ ORANGE (-) AT MODULE TO RIGHT OF STEERING COLUMN
Trunk Trigger BROWN / WHITE (+) AT SWITCH IN TRUNK
Alarm Disarm BLUE/BLACK (-) IN DRIVER'S DOOR
Parking Lights WHITE/ BLACK (-) AT HEADLIGHT SWITCH
Convenience
WIRE COLOR POLARITY LOCATION
Headlights-Lo RED / YELLOW (+) IGNITION SWITCH HARNESS
Wipers-Lo DARK BLUE/ORANGE (+) IGNITION SWITCH HARNESS
Trnk Release VIOLET / YELLOW (+) IN HARNESS IN DRIVERS KICKPANEL
Remote Start
WIRE COLOR POLARITY LOCATION
Battery LT. GREEN/ VIOLET AND YELLOW (+) AT IGNITION SWITCH HARNESS
Ignition 1 WHITE/ YELLOW (+) AT IGNITION SWITCH HARNESS
Ignition 2 BLACK/ GREEN (+) AT IGNITION SWITCH HARNESS
Accessory 1 PINK/BLACK (+) AT IGNITION SWITCH HARNESS
Accessory 2 GRAY / YELLOW (+) AT IGNITION SWITCH HARNESS
IF THERE IS A 2ND GRAY / YELLOW PRESENT YOU WILL HAVE TO ENERGIZE IT.
Starter 1 RED / BLUE (+) AT IGNITION SWITCH HARNESS
Anti-Theft Type FORD PATS SYSTEM
Anti-Theft Descript RF TYPE SYSTEM
Key Sense BLACK/ PINK (-) AT 6-WAY PLUG TO THE RIGHT OF STEERING COLUM
THIS PLUG CONTAINS AIR BAG WIRES. PLEASE MAKE SURE THAT YOU DO NOT TAP INTO THEM.
Tachometer TAN/BLACK (AC) AT DRIVER'S SIDE FUEL INJECTOR
YOU CAN ALSO US ANY OF THE UNCOMMON WIRES AT ANY FUEL INJECTOR.
Speed Sense GRAY/BLACK (AC) IN HARNESS IN DRIVERS KICKPANEL
Parking Lights WHITE/ BLACK (-) AT HEADLIGHT SWITCH
Brake Lights GREEN (+) AT BRAKE SWITCH
Reverse Lights BLACK/ PINK (+) IN HARNESS IN DRIVERS KICKPANEL TO REAR
Horn BLUE (-) AT 6-WAY PLUG TO THE RIGHT OF STEERING COLUM
THIS PLUG ALSO CONTAINS AIR BAG WIRE. PLEASE MAKE SURE THAT YOU DO NOT TAP INTO THEM.
Modules
WIRE LOCATION
Please select another category
Doorlocks/Windows
WIRE COLOR POLARITY LOCATION
Power Unlock PINK/GREEN (+) IN DRIVER'S DOOR
VEHICLES W/O FACTORY KEYLESS HAVE REV POLARITY DOOR LOCK SYSTEM. WIRE IS THE SAME COLOR, INTERUPT WIRES IN DRIVER'S DOOR BOOT.
PowerLock PINK / YELLOW (+) IN DRIVER'S DOOR
VEHICLES W/O FACTORY KEYLESS HAVE A REVERSE POLARITY DOOR LOCK SYSTEM. WIRE IS THE SAME COLOR, INTERUPT WIRE IN DRIVER'S DOOR BOOT.
Driver Mtr Unlock RED / ORANGE (+) IN DRIVER'S DOOR
Driver Mtr Lock RED / ORANGE (+) IN HARNESS IN DRIVERS KICKPANEL
DIRECTWIRE WIRING INFORMATION - MERCURY / GRAND MARQUIS / 2004 / Security
12volts brown and lt. green + ignition harness
Starter RED / lt. blue + ignition harness
Ignition WHITE/ yellow + ignition harness
Power Lock pink / YELLOW driver kick, door harness
Notes: Without keyless entry the door locks are 5wi (reverse polarity). With keyless entry they are positive trigger.
Power Unlock pink/lt. green driver kick, door harness
Notes: Without keyless entry the door locks are 5wi (reverse polarity). With keyless entry they are positive trigger.
Lock Motor pink/black 5wi driver kick, door harness
Unlock Motor RED / orange 5wi driver door motor in door
Disarm Defeat pink/orange 5wi driver kick, harness to rear
Parking Lights+ brown + pin 4, blk plug @ LCM
Notes: The LCM (Lighting Control Module) is to the right of the steering column.
Parking Lights- WHITE/ black - pin 13, gry 16P plug @ LCM
Notes: The LCM (Lighting Control Module) is to the right of the steering column.
Hazards same as turn signals
Turn Signal(L) lt. GREEN/ orange + steering column
Turn Signal(R) ORANGE / lt. blue + steering column
Door Trigger dk. blue and BLACK/ orange - LCM
Notes: Blue is the driver door trigger wire, it is in pin 11, gray 22 pin plug. BLACK/ orange is the three passenger doors, it is in pin 11, gray 16 pin plug. Use both wires and diode isolate each.
The LCM (Lighting Control Module) is to the right of the steering column.
Dome Supervision use door trigger
Trunk/Hatch Pin BROWN / white - pin 5, gry 16P plug @ LCM
Notes: The LCM (Lighting Control Module) is to the right of the steering column.
Hood Pin N/A
Trunk/Hatch Release purple / YELLOW 5wi driver kick, harness to rear
Notes: The fuel door release is WHITE/ pink (+) in the driver kick, harness to rear.
Power Sliding Door N/A
Factory Alarm Arm N/A
Factory Alarm Disarm N/A
Disarm No Unlock N/A
Tachometer NOT red or RED / lt. grn ac any ignition coil or injector
Horn Trigger dk. blue - steering column
Memory Seat 1 N/A
Memory Seat 2 N/A
Memory Seat 3 N/A