Which parts fail
Components named in complaints (headlights, tail lights, turn signals, interior lights).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2003 Mercury Grand Marquis owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2003 Mercury Grand Marquis. The contact that the headlights were intermittently inoperable. Additionally, the contact stated that the instrument panel lights, the brake lights, and the turn signal lights were inoperable. The contact who is a mechanic, had inspected the fuses, the fuse box, and other unknown parts, but found no failures. The dealer was notified of the failure. The vehicle was not diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 15V861000 (Exterior Lighting); however, the VIN was not included. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 160,000.
The contact owns a 2003 Mercury Grand Marquis. The contact stated that upon purchase of the vehicle, he received notification of NHTSA Campaign Number: 15V861000 (Exterior Lighting). Over time, the contact stated that the headlights and taillights would intermittently fail to operate without warning. The vehicle was taken to the dealer and the recall repair was performed. Despite the recall repair, the contact stated that the taillights failed to operate. The dealer was informed of the failure and the contact was informed that he had to pay out of pocket for the repair. The manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 190,000.
The contact owns a 2003 Mercury Grand Marquis. The contact stated that while driving at an undisclosed speed, the front headlights shutoff independently while turned on. No warning light was illuminated. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The contact who is an independent mechanic determined that the lighting control module (LCM) needed to be replaced. Upon further investigation, the contact related the failure to NHTSA Campaign Number: 15V861000 (Exterior Lighting); however, the VIN was not included. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 285,000.
The contact owns a 2003 Mercury Grand Marquis. The contact stated that the headlights and taillights were inoperable, and the trunk failed to open. Additionally, all the doors failed to manually lock, and while utilizing the key fob, the door locks were inoperable. The door-ajar message was displayed. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline. The contact stated that the failure was related to NHTSA Campaign Number: 15V861000 (Exterior Lighting). The approximate failure mileage was 179,000. The VIN was not available.
The contact owns a 2003 Mercury Grand Marquis. The contact stated while driving at an undisclosed speed, the headlights failed to operate as needed. The vehicle was taken to an independent mechanic, where it was diagnosed and determined that the lighting control module needed to be replaced. The vehicle was not repaired. The contact stated that the vehicle had previously been repaired under NHTSA Campaign Number: 15V861000 (Exterior Lighting). The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 181,000.
The contact owns a 2003 Mercury Grand Marquis. The contact stated that while the vehicle was parked, the contact noticed that the headlights were inoperable. There was no warning light illuminated. The vehicle was taken to an independent mechanic where it was diagnosed that the lighting control module had failed and needed to be replaced. The vehicle was not repaired. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHSTA Hotline for assistance. The failure mileage was approximately 106,000.
The contact owns a 2003 Mercury Grand Marquis. The contact stated that upon turning on the headlights, the taillights intermittently failed to illuminate. There was no warning light illuminated. The contact called two local dealers and was informed that there were no open recalls associated with the VIN. The manufacturer was also notified of the failure and a complaint was filed. The manufacturer informed the contact that the vehicle was previously repaired under NHTSA Campaign Number: 15V861000 (Exterior Lighting). The vehicle was not repaired. The failure mileage was approximately 148,000.
The contact owns a 2003 Mercury Grand Marquis. The contact stated while driving 75 MPH at night, the brake lights, headlights, and taillights failed to illuminate as needed. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The contact stated that the lighting control module was the cause of the failure. The manufacturer was made aware of the failure and referred the contact to file a complaint with the NHTSA Hotline. The failure mileage was approximately 101,000.
The contact owns a 2003 Mercury Grand Marquis. The contact stated that the vehicle was previously repaired under Technical Service Bulletin: 14N01 (Lighting Control Module); however, the contact stated that while driving at an undisclosed speed, the headlamps flashed and then completely failed to remain illuminated. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 121,236.
The contact owns a 2003 Mercury Grand Marquis The contact stated that both the headlamps and the taillights intermittently failed to operate as needed. There were no warning lights illuminated. The vehicle was taken to the dealer and was diagnosed. The dealer placed a processor on the vehicle and rewired the lights however, the failure persisted. The manufacturer was not made aware of the failure. The manufacturer was not made aware of the failure. The failure mileage was 127,000.
Related recalls
Exterior lighting › Headlights
Ford Motor Company (Ford) is recalling certain model year 2003-2005 Ford Crown Victoria and Mercury Grand Marquis vehicles manufactured October 3, 2001, to August 2, 2005. The affected vehicles have a lighting control module (LCM) that may fail, resulting in a loss of headlights.
Remedy: Ford will notify owners, and dealers will replace the LCM, free of charge. The recall began April 14, 2017. Owners may contact Ford customer service at 1-866-436-7332. Ford's number for this recall is 15S39.
NHTSA investigations
Loss of headlights
The Office of Defects Investigation (ODI) opened an investigation concerning the loss of headlights in model year (MY) 2003-2005 Ford Crown Victoria and Mercury Grand Marquis vehicles. The subject vehicles share the same architecture and major components.ODI has received 636 unique reports (for all submission dates) related to the alleged defect, with owners describing a loss of both low and/or high beam headlights…
Loss of headlight function
The agency has closed this investigation based on its review of complaint reports, field and technical data provided by Ford and complainant interviews. Ford found that some lighting control modules (lcm) in the subject vehicles contained defective solder joints on the printed circuit board.this condition can lead to poor headlight performance ranging from intermittent outage and dimming to eventual headlights…
Loss of headlamp/exterior lighting
In a letter dated October 2, 2014 the Office of Defects Investigation (ODI) was initially petitioned by the North Carolina Consumers Council, Inc. requesting a defect investigation of an alleged defect condition resulting in headlight and/or exterior lighting failure on 2003-2005 Ford Crown Victoria and Mercury Grand Marquis vehicles.ODI analyzed Vehicle Owner Questionnaire (VOQ) complaints received from consumers…
Headlight complaints in other Grand Marquis years
Frequently asked questions
How common are headlight problems on the 2003 Mercury Grand Marquis?
NHTSA has 207 complaints about the lights of the 2003 Mercury Grand Marquis, 57% of the model year's 362 complaints. The component named most often is headlights (19 mentions).
Is there a recall for 2003 Mercury Grand Marquis headlight problems?
Yes — NHTSA recall 15V-861 (headlights, Dec 22, 2015). Recall repairs are free at authorized dealers.
At what mileage do 2003 Mercury Grand Marquis headlight problems start?
Half of the complaints with a recorded mileage happened before about 95,000 miles, and 1% before 25,000 miles.
Is it dangerous?
Owners linked 5 crashes, 0 fires and 1 injury to lights problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.